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ISSN 1560–7259 (print edition)
TURCZANINOWIA
ISSN 1560–7267 (online edition)
УДК 582.394:581.4
Preliminary checklist of Hoya (Asclepiadaceae) in the ora of
Cambodia, Laos and Vietnam
L. V. Averyanov1, Van The Pham2, T. V. Maisak1, Tuan Anh Le3, Van Canh Nguyen4, Hoang Tuan
Nguyen5, Phi Tam Nguyen6, Khang Sinh Nguyen2, Vu Khoi Nguyen7, Tien Hiep Nguyen8, M. Rodda9
1 Komarov Botanical Institute, Prof. Popov, 2; St. Petersburg, RF-197376, Russia
E-mails: av_leonid@mail.ru; av_leonid@yahoo.com
2 Institute of Ecology and Biological Resources, Vietnam Academy of Sciences and Technology, 18 Hoang Quoc Viet,
Cau Giay, Ha Noi, Vietnam. E-mail: phamvthe@gmail.com
3Quang Tri Center of Science and Technology, Mientrung Institute for Scientic Research, 121 Ly Thuong Kiet, Dong Ha,
Quang Tri, Vietnam. E-mail: tasa207@gmail.com
4 3/12/3 Vo Van Kiet Street, Buon Ma Thuot City, Dak Lak province, Vietnam. E-mail: nguyenvancanh@gmail.com
5Department of Pharmacognosy, Hanoi University of Pharmacy, 15 Le Thanh Tong, Hoan Kiem, Hanoi, Vietnam
E-mail: tuandl50@yahoo.com
6Viet Nam Post and Telecommunications Group – VNPT, Lam Dong 8 Tran Phu Street, Da Lat City,
Lam Dong Province, Vietnam. E-mail: phitam77@gmail.com
7Wildlife At Risk, 202/10 Nguyen Xi st., ward 26, Binh Thanh, Ho Chi Minh, Vietnam. E-mail: nvkhoi70@gmail.com
8Center for Plant Conservation, no. 25/32, lane 191, Lac Long Quan, Nghia Do, Cau Giay District, Ha Noi, Vietnam
E-mail: hiep.nguyen@cpcvn.org
9Herbarium, Singapore Botanic Gardens, 1 Cluny Road, Singapore 259569. E-mail: rodda.michele@gmail.com
Key words: Asclepiadaceae, Cambodia, eastern Indochina, endemism, ora, Hoya, Laos, plant diversity, plant
taxonomy, Vietnam.
Summary. This paper provides new data on 33 new or rare species of Hoya obtained in eldwork mainly during
2012–2017 in eastern Indochina including Cambodia, Laos and Vietnam. These data include illustrated descriptions
of three species new for science, as well as illustrated records of 24 species new for the oras of the studied countries.
When these new data are included, the ora of eastern Indochina comprises at least 45 species. Among them eight
species are recorded and documented for Cambodia, 21 sp. for Laos and 40 sp. for Vietnam; two new species are de-
scribed in Vietnam (H. crassipetiolata and H. nutans) and one species is described from Laos (H. uniora). Eighteen
species were recorded newly for the ora of Vietnam (H. arnottiana, H. burmanica, H. chinghungensis, H. erythrina,
H. erythrostemma, H. fungii, H. grifthii, H. hainanensis, H. lanceolata, H. linearis, H. loyceandrewsiana, H. meng-
tzeensis, H. nummularioides, H. pachyclada, H. pandurata, H. parviora, H. revolubilis, H. vaccinioides), nine for
Laos (H. arnottiana, H. carnosa, H. chinghungensis, H. fungii, H. globulosa, H. grifthii, H. linearis, H. pandurata,
H. polyneura) and two for Cambodia (H. lobbii, H. multiora). New localities were discovered for H. bonii,
H. lockii, H. lyi, H. micrantha, H. multiora, H. oblongacutifolia, and H. verticillata known earlier in Cambodia, Laos
and Vietnam by few collections. Lectotypes are proposed for the following eight species: H. arnottiana, H grifthii,
H. lanceolata, H. lobbii, H. nummularioides, H. oblongacutifolia, H. pachyclada, and H. vaccinioides. Names of ve
taxa earlier known as separate species (H. villosa, H. pseudovalifolia, H. graveolens, H. balansae) are regarded as
synonyms of H. globulosa, H. micrantha, H. oblongacutifolia, H. verticillata respectively.
Поступило в редакцию 08.06.2017 Submitted 08.06.2017
Принято к публикации 08.09.2017 Accepted 08.09.2017
Turczaninowia 20 (3): 103–147 (2017)
DOI: 10.14258/turczaninowia.20.3.10
http://turczaninowia.asu.ru
104 Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
Предварительный список видов Hoya (Asclepiadaceae) во флоре
Камбоджи, Лаоса и Вьетнама
Л. В. Аверьянов1, Ван Те Фам2, T. В. Maйсак1, Tуан Aнь Ле3, Ван Кань Нгуен4, Хоанг Туан Нгуен5,
Фи Там Нгуен6, Кхань Синь Нгуен2, Ву Кхой Нгуен7, Tьен Хьеп Нгуен8, M. Родда9
1Ботанический институт им. В. Л. Комарова РАН, ул. Проф. Попова, 2; Санкт-Петербург, 197376, Россия
2 Институт экологи и биологических ресурсов, Академии наук и технологии Вьетнама, 18 Хоанг Куок Вьет,
Кай Зяу, Ханой, Вьетнам
3 Научно-технологический Центр Куанг Чи, Миентрунг Институт Научных Исследований, 121, Ли Туонг Кьет,
Донг Ха, Куанг Чи, Вьетнам
4 3/12/3 Во Ван Кьет, Банметуот, повинция Даклак, Вьетнам
5 Отдел Фармакогнозии, Университет Фармакологии г. Ханоя, 15 Ле Тханг Тонг, Хоан Кием, Ханой, Вьетнам
6 “Почта и Телекоммуникации Вьетнама – ВНПТ”, Лам Донг 8 Чан Фу, Далат, провинция Лам Донг, Вьетнам
7 “Дикая Природа в Опасности”, 202/10 Нгуен Си, Вард 26, Бинь Тханх, Хо Ши Мин, Вьетнам
8 Центр охраны растений, № 25/32, линия 191, Лак Лонг Куан, Ни До, Кай Гау, Ханой, Вьетнам
9 Ботанический сад Сингапура, 1 Клани Роад, Сингапур, 259569
Ключевые слова: восточный Индокитай, Вьетнам, Камбоджа, Лаос, разнообразие растений, таксономия рас-
тений, флора, эндемизм, Asclepiadaceae, Hoya.
Аннотация. Статья содержит сведения о 33 новых и редких видах рода Hoya, полученные в ходе поле-
вых работ, проводившихся на протяжении 2012–2017 гг. в восточном Индокитае, включающем территорию
Камбоджи, Лаоса и Вьетнама. Полученные результаты включают иллюстрированные описания 3 видов, но-
вых для науки, а также 24 видов, новых для флор изучаемых стран. С учетом этих данных флора восточного
Индокитая насчитывает как минимум 45 видов рода, произрастание восьми из которых задокументировано
для Камбоджи, 21 – для Лаоса и 40 – для Вьетнама. Два новых для науки вида описаны из Вьетнама (H. cras-
sipetiolata и H. nutans) и один – из Лаоса (H. uniora). 18 видов впервые указываются для флоры Вьетнама
(H. arnottiana, H. burmanica, H. chinghungensis, H. erythrina, H. erythrostemma, H. fungii, H. grifthii, H. haina-
nensis, H. lanceolata, H. linearis, H. loyceandrewsiana, H. mengtzeensis, H. nummularioides, H. pachyclada,
H. pandurata, H. parviora, H. revolubilis, H. vaccinioides), 9 – для флоры Лаоса (H. arnottiana, H. carnosa, H. chin-
ghungensis, H. fungii, H. globulosa, H. grifthii, H. linearis, H. pandurata, H. polyneura) и 2 – для флоры Камбоджи
(H. lobbii, H. multiora). Выявлены новые местонахождения ряда редких видов (H. bonii, H. lockii, H. lyi, H. mi-
crantha, H. multiora, H. oblongacutifolia и H. verticillata), известных ранее в восточном Индокитае по единич-
ным сборам. Для 8 видов (H. arnottiana, H grifthii, H. lanceolata, H. lobbii, H. nummularioides, H. oblongacutifolia,
H. pachyclada и H. vaccinioides) выбраны лектотипы. Названия 5 таксонов, принимаемых ранее в качестве
самостоятельных видов (H. villosa, H. pseudovalifolia, H. graveolens, H. balansae), сведены в синонимы к сле-
дующим принятым ныне видам: H. globulosa, H. micrantha, H. oblongacutifolia, H. verticillata, соответственно.
Introduction
The genus Hoya R. Br. (Brown, 1810) includes
350–450 currently accepted species found through-
out tropical Asia, tropical Pacic islands and NE
Australia (Li et al., 1995; Forster, Liddle, 1996; For-
ster, 2006; Liddle, 2009; Rodda, 2015). Mainland
southeast Asia and particularly the Indochinese Pen-
insula should be presently recognized as one of the
richest areas of the genus species diversity with 41
species recorded up to now in Thailand (Thaithong,
2001; Kidyoo, Thaithong, 2007a, b), 32 species in
southern China (Li et al., 1995), 26 species in Vi-
etnam (Costantin, 1912; Pham, 2003; Tran, 2005;
Tran et al., 2011a, b; Pham, Averyanov, 2012; The,
Averyanov, 2012; Rodda et al., 2012, 2015; Rodda,
Simonsson Juhonewe, 2013; Pham et al., 2015), 19
species in Myanmar (Kress et al., 2003), 10 species
in Lao PDR (Newman et al., 2007, Rodda, 2012;
Rodda et al., 2015) and ve species in Cambodia
(Costantin, 1912). Meanwhile, countries of east-
ern Indochina including Cambodia, Laos and Vi-
etnam certainly rich in Hoya species remain up to
the present study insufciently studied. This paper
provides illustrated description of three species new
for science (H. crassipetiolata, H. nutans, H. uni-
ora), as well as illustrated records of 24 species
105
Turczaninowia 20 (3): 103–147 (2017)
new for the oras of Cambodia, Laos and Vietnam.
When these new data are included, ora of eastern
Indochina including Cambodia, Laos and Vietnam
encompasses at least 45 species (Table 1). Among
them, eight species are recorded and documented
for Cambodia, 21 sp. for Laos and 40 sp. for Viet-
nam; two new species are described from Vietnam
(H. crassipetiolata and H. nutans) and one from Laos
(H. uniora). Eighteen species are newly recorded for
the ora of Vietnam (H. arnottiana, H. burmanica,
H. chinghungensis, H. erythrina, H. erythrostemma,
H. fungii, H. grifthii, H. hainanensis, H. lanceola-
ta, H. linearis, H. loyceandrewsiana, H. mengtzeen-
sis, H. nummularioides, H. pachyclada, H. pandu-
rata, H. parviora, H. revolubilis, H. vaccinioides),
nine for Laos (H. arnottiana, H. carnosa, H. chin-
ghungensis, H. fungii, H. globulosa, H. grifthii,
H. pandurata, H. polyneura), and two for Cambodia
(H. lobbii, H. multiora). New localities are discov-
ered for H. bonii, H. lockii, H. lyi, H. micrantha,
H. multiora, H. oblongacutifolia and H. verticil-
lata previously known in Cambodia, Laos and Viet-
nam based on few collections. Lectotypes are pro-
posed for nine species. These species are H. ar-
nottiana, H. globulosa, H grifthii, H. lanceolata,
H. lobbii, H. nummularioides, H. oblongacutifolia,
H. pachyclada, and H. vaccinioides. Names of
ve taxa previously accepted as distinct species
(H. villosa, H. pseudovalifolia, H. graveolens,
H. balansae) are regarded as synonyms of
H. globulosa, H. micrantha, H. oblongacutifolia,
H. verticillata respectively. Table 1
Species of Hoya R. Br. reported in the ora of Cambodia, Laos and Vietnam
(Costantin, 1912; Tran, 2005; Pham, 2003; Tran et al., 2011b; Pham, Averyanov, 2012; Rodda, 2012; Rod-
da, Simonsson Juhonewe, 2012a, b; 2013; Rodda et al., 2012, 2013, 2015; Pham, Averyanov 2012; Pham
et al., 2015).
Hoya arnottiana Wight [L**, V**]
H. bonii Costantin [V*]
H. burmanica Rolfe [V**],
H. carnosa (L. f.) R. Br. [L**]
H. chinghungensis (Tsiang et P. T. Li) M. G. Gilbert, P.
T. Li et W. D. Stevens [L**, V**]
H. crassipetiolata Aver., V. T. Pham et T. A. Le [V***]
H. diversifolia Blume [C, L, V]
H. erythrina Rintz [V**]
H. erythrostemma Kerr [V**]
H. chinghungensis (Tsiang et P. T. Li) M. G.Gilbert et
al. [L**, V**]
H. fungii Merr. [L**, V**]
H. fusca Wall. [C, L, V]
H. globulosa Hook. f. [L**, V]
H. grifthii Hook. f. [L**, V**]
H. hainanensis Merr. [V**]
H. hanhiae V. T. Pham et Aver. [V]
H. ignorata T. B. Tran et al. [V]
H. kerrii Craib [L, V]
H. lanceolata D. Don [V**]
H. linearis Wall. ex D. Don [L**, V**]
H. lobbii Hook. f. [C**]
H. lockii V. T. Pham et Aver. [V*]
H. longipedunculata V. T. Pham et Aver. [V]
H. loyceandrewsiana T. Green [V**]
H. lyi H. Lév. [V*]
H. mengtzeensis Tsiang et P. T. Li [V**]
H. micrantha Hook. f. [C*, L*, V*]
H. minima Costantin [V]
H. multiora Blume [C**, L*, V*]
H. nummularia Hook. f. [V]
H. nummularioides Costantin [C, L, V**]
H. nutans V. T. Pham et Aver. [V***]
H. oblongacutifolia Costantin [V*]
H. pachyclada Kerr [C, L, V**]
H. pandurata Tsiang [L**, V**]
H. parviora Wight [V**]
H. polyneura Hook. f. [L**]
H. revolubilis Tsiang et P. T. Li [V**]
H. sapaensis T. B. Tran et Rodda [V]
H. tamdaoensis Rodda et T. B. Tran [V]
H. thuathienhuensis T. B. Tran et al. [V]
H. uniora Aver. et V. T. Pham [L***]
H. vaccinioides Hook. f. [L, V**]
H. vangviengiensis Rodda et Simonsson [L]
H. verticillata (Vahl.) G. Don [C*, L, V*]
Legend for the table. The occurrence of each species in Cambodia, Laos and Vietnam is designated by letters “C”,
“L” and “V” respectively (placed in square brackets after the name), rediscoveries for these countries are marked by
one asterisk “*”; new records for countries respectively are marked by double asterisk “**”, species described as new
for science are marked with triple asterisk “***”, names of rare and critical species recorded in this paper are displayed
in bold font. The following species have also been recorded for Vietnam, but are erroneous: Hoya wallichiana Decne
(Decaisne, 1844), H. wallichii (Wight) C. M. Burton (Wight, 1834; Burton, 1996; Rodda et al., 2016), H. macrophylla
Blume (Blume, 1826); H. cochinchinensis (Lour.) Schult. (Loureiro, 1790; Schultes, 1820), has been identied as an
earlier name for H. verticillata (Vahl) G. Don (Vahl, 1810; Don, 1838) and has been proposed for rejection (Rodda,
2016); H. reticulata Costantin (Costantin, 1912) is a nom. illeg., non Hoya reticulata Moon (Moon, 1824) and is
conspecic with H. multiora (Blume, 1823); H. pseudolanceolata Costantin (Costantin, 1912) is based on fruiting
material that appears to belong to Aeschynanthus sp.
106
Materials and methods
Materials suitable for studies were eld collected
mainly during 2012–2017. Herbarium studies at
IBSC, P and SING and some previously gathered
herbarium specimens and living collections provided
signicant additional information for the current
investigation. Fresh inorescences and owers
were xed and preserved in 60–70 % ethanol.
Measurements of oral parts for descriptions were
made on both living and liquid-preserved materials.
Fresh owers or oral parts were found to shrink up
to ca 15–25 % in size in the drying process of making
herbarium specimens. It is noteworthy that oral
parts of Hoya species shrink often disproportionally,
in particular the corona contracts less than sepals
and petals. This was taken into account when dried
herbarium specimens were studied. In describing
quantitative characters, infrequent extreme values
(i.e. rarely occurring minimal and maximal values)
of a variation range are parenthesized respectively
before and after a normal variation range.
The annotated list of all discovered species
is presented below. Paragraphs for species are
arranged in the list according to species name in
alphabetic order. The annotation for each species
includes following data in separate lines:
– valid name and main synonyms, occurring in
regional literature;
– data about type or original materials;
– living form, summarized available data on
ecology, habitat elevation, phenology and observed
rarity;
– distribution in studied countries (mostly
by listing of the country provinces) and general
distribution;
– short notes on taxonomy, expected relations
and/or biology;
– abbreviated and unied text of herbarium labels
including geographical locality, collection date,
collectors’ names, collection number and acronym
of herbarium where mentioned specimen is housed.
Color and line illustrations of voucher specimens
are provided for almost all recorded species. Species
distribution in countries of eastern Indochina is
indicated in the text by mentioning concerned
provinces according to the current ofcial
administrative division. Online version of the IUCN
Red List of Threatened Species (2016) was used
for estimation of preliminary species conservation
status.
Annotated list of new, rare and critical Hoya
species in the ora of Cambodia, Laos and
Vietnam
Hoya arnottiana Wight,
1834, Contr. Bot. India: 37.
Fig. 1.
Described (Wight, 1834) from Nepal (“In Ne-
pal”). Lectotype (“Wallich, Asclep. no. 35. Her-
barium Robert Wight Proper”) – K [K000873110!],
isolectotype – E [E00179574!]; lectotype here des-
ignated.
Noltie (2005) indicated type of H. arnottiana
‘Nepal’ (Sillet), Wallich, Wall. Asclep. 35 [= Wall.
Cat. 8161] (E!, K!). A specimen labelled HRWP
(Herbarium Robert Wight Proper) and annotated
“35. Hoya arnottiana RW Nepal” is present at K and
is here selected as lectotype.
Vernacular name in Vietnam. Cẩm cù chẻ.
Description. Epiphytic and lithophytic vine with
milky latex 2–4 m long. Stem dull pale greenish-
grey, young brown-grey hairy, old glabrous, slender,
weak, terete, 2.5–3 mm in diam., twining or climbing
by adventitious roots; internodes 5–20 cm long.
Leaves petiolate, decussate. Petiole brown–grey
hairy, thick, terete, dark green, curved, often upward,
1.7–2 cm long, 2.5–3 mm in diam. Leaf blade rather
eshy, elliptic, 8.5–10.5 cm long, 3.5–6 cm wide,
cuneate or round at base, acuminate and curved at
apex, adaxially glabrous, dark green, glossy, margin
often slightly incurved, net-veined, lateral veins in
4–5 pairs; abaxial surface whitish-green, pubescent
with brown-grey hairs, prominent midrib and visible
lateral veins. Inorescence an extra-axillary many-
owered umbel, with up to 40 owers, hemispheric;
peduncle rather stout, straight, cylindrical, swollen
at base and apex, brown–grey hairy, 3.5–7 cm
long, 2.5–3 mm in diam. at narrower part, 5.5–5.8
mm in diam. at thicker parts, light olive- greenish;
pedicels white to light greenish, cylindrical, slender,
21.5–22.5 mm long, 0.8–1 mm in diam., glabrous.
Flowers almost white. Calyx at, 5.4–5.6 mm in
diam., shortly, sparsely hairy, of 5 sepals joined at
base, sepals yellowish-white, triangular narrowly
ovate, acute, 1.8–2.2 mm long, 1.3–1.7 mm wide
near base. Corolla of 5 petals, being attened 1.65–
1.75 cm in diam., white; petals reexed, margin and
apex revolute, rhomboid, connate, 7.8–8.5 mm long,
4.8–5.3 mm wide, triangular acute at apex, outsides
glabrous, inside shortly pubescent. Corona glossy,
pure white, sometime with light pink tint in center,
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
107
Fig. 1. Hoya arnottiana Wight. Digital Vietnamese ora 0260/PVT BT 012-2012. Photos by V. T. Pham, correction
and design by L. Averyanov and T. Maisak.
Turczaninowia 20 (3): 103–147 (2017)
108
of 5 segments, 2 mm tall, 8.6–8.8(9) mm in diam.,
grooved between segments; segments obliquely
ellipsoid in outline, little concave above, 4.3–4.8
mm long, 2.4–2.7 mm wide, outer angle acute,
notched of bid into two small unequal teeth, inner
angles shortly acuminate, not reaching gynostegium
apex. Gynostegium with 5 pollinaria covered by
scarious, yellowish anther caps. Pollinarium with
minute corpusculum, hardly visible translators
and 2 pollinia; corpusculum narrowly rhomboid,
angled, with two small wings beside, grooved,
chestnut-brown, 0.10–0.11 mm long, 0.24–0.26
mm wide; translators very short, about 0.03 mm
long; pollinia oblong, 0.6–0.7 mm long, 0.2–0.25
mm wide, yellow; germinating crest very narrow,
light yellowish, hyaline, extending from translator
to pollinium apex. Ovary of 2 carpels, free, bottle-
shaped. Carpels half bottle-shaped, connivent each
other, 1.4–1.5 mm tall, 0.5–0.7 mm in diam.
Habitat, phenology and conservation status.
Epiphytic semi-woody vine about 3 m long. Primary
evergreen seasonal broad-leaved closed submontane
forest on basalt, 1500–1550 m. Fl. April – June. Not
common. Estimated IUCN Red List status – DD.
Distribution. Laos (Houaphan province),
Vietnam (Dak Lak and Thanh Hoa provinces).
India, Thailand.
Notes. This new record for the oras of Laos
and Vietnam considerably extends the distribution
area of Hoya arnottiana that was so far only known
from Nepal and India (Assam, Meghalaya, Sikkim
and West Bengal). The species was also collected
in northern Thailand (Chiang Mai), but without ex-
act locality (M. Rodda MR 574, SING). The spe-
cies is insufciently known in Indochina, hence we
provide here its full description based on personally
studied Laotian and Vietnamese specimens.
Studied specimens. Northern Laos, Houphan
province, Viengxay district, Xieng Luong village,
around point 20°22′06.1′′N, 104°17′18.6′′E, primary
and secondary broad-leaved evergreen dry forest on
limestone at 600–700 m, semi-woody vine 2–3 m long
on open mossy rocks, owers entirely white, strong
sweet fragrant, common, 8 April 2015, N. T. Hiep,
L. Averyanov, N. S. Khang et al., LA-VN 1156 (FOF,
HNL, LE – photos). Northern Laos, Houphan prov-
ince, Vieng Thong district, Nam Et – Phou Louey
Natural protected area, Tad Hokdon WF, disturbed
primary forest, along stream, 802 m, 20°06′21.6′′N,
103°22′15.2′′E, 7 June 2013, J. Leong-Skornickova
et al., JLS-2394 (E, Pha Tad Ke, P, QBG, SING).
Northern Vietnam, Thanh Hoa province, Ba Thuoc
district, Thanh Son municipality, SW macro-slope
of middle part of Pu Luong range around point
20º28’30’’N, 105º05’16’’E, primary evergreen
seasonal broad-leaved closed submontane forest
on basalt at elev. 1500–1550 m, epiphytic vine,
occasional, 10 October 2003, L. Averyanov et al.,
HAL 4272 (LE, LE – photos). Southern Vietnam,
Dak Lak province, sine loc., N. V. Canh s. n., 2014
(LE – photos). Plate: digital Vietnamese ora 0260/
PVT BT 012-2012, g. 1.
Hoya bonii Costantin,
1912, Fl. Indo-Chine 4: 140; Pham H. H., 2003,
Ill. Fl. Vietnam 2: 747, g. 6989; Tran T. B., 2005,
Checklist Pl. Sp. Vietnam 3: 66.
Fig. 2.
Described from central Vietnam (“Vo Xa (?)
Mountain”). Type (“Tonkin occidental, in introitu
montium Vòxà, R. P. Bon 2703, 1884-6-19”) – P
[syntypes – P00645998, P00645999, P00646000].
Vernacular name in Vietnam. Cẩm cù bon.
Habitat, phenology and conservation status.
Epiphytic and lithophytic vine to 5 m long with
yellow latex. Secondary evergreen, broad-leaved,
limestone forests close to the sea, 0–100 m. Fl. May.
Locally very common. Estimated IUCN Red List
status – VU.
Distribution. Vietnam (Hai Phong and Quang
Ninh province). Endemic.
Notes. This is the rst rediscovery of this spe-
cies since more than 100 years from its description
in 1884 when it was recorded without indication of
exact locality of type collection. Although this spe-
cies is locally common, it has restricted distribution
in an area less than 150 km2. In corolla and corona
morphology, the species is similar to H. fungii Merr.
(Merrill, 1934) or H. carnosa (L. f.) R. Br. (Linne,
1782; Brown, 1810) but distinguishes in leaves
cordate at the base (rarely round), hairy below and
along margin. The variation of H. carnosa has not
been studied in detail yet and it may be possible that
further studies will bring to synonymise H. bonii
with H. carnosa.
Studied specimens. Northern Vietnam, Hai
Phong province, Cat Hai district, Viet Hai village,
Cat Ba national park around point 20°46′N, 107°1′E,
0–100 m, secondary limestone forest close to sea,
epiphytic or lithophytic vine to 5 m long with yel-
low latex, leaves thick, variable in shape, leaf base
cordate, apex acute, young peduncles and stems
brown hairy, mature glabrous, umbels with 12 to
32 owers, owers white with pinkish-red corona,
chocolate fragrant at night, open till midday, locally
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
109
Fig. 2. Hoya bonii Costantin. Digital Vietnamese ora 0261/PVT CB 001-2012. Photos by V. T. Pham, correction and
design by L. Averyanov and T. Maisak.
Turczaninowia 20 (3): 103–147 (2017)
110
very common, 22 May 2016, P. V. The, Kirrily, PVT
CB 001-2016 (HN, LE). Plate: digital Vietnamese
ora 0261/PVT CB 001-2012, g. 2.
Hoya burmanica Rolfe,
1920, Bull. Misc. Inform. Kew 10: 343; Rodda,
Simonsson Juhonewe, 2012 , Kew Bull. 67: 1.
Fig. 3A–C.
Described (Rolfe, 1920) from Myanmar (“Bur-
ma: Chin Hills”). Lectotype (“Cult. in Hort.
Bot. Reg. Kew A. 191, Aug. 1920, s. n.”) – K
[K000449127], lectotype designated by Rodda and
Simonsson Juhonewe (2012a).
Vernacular name in Vietnam. Cẩm cù burma.
Habitat, phenology and conservation status.
Lithophytic and occasionally epiphytic undershrub
with pendulous shoots to 1 m long. Primary evergreen
broad-leaved humid forests on rocky limestone,
commonly on shady cliffs at mountaintops, 1350–
1500 m. Fl. April – August. Very rare. Estimated
IUCN Red List status – EN.
Distribution. Vietnam (Dien Bien province).
NE India, N Myanmar, N Thailand.
Notes. The discovery of H. burmanica in north-
western Vietnam considerably expands the known
distribution area of this species to the east. It grows
in Vietnam in humid evergreen forests, a rather dif-
ferent environment from the seasonally dry open
woodlands where it can be found in Myanmar. In
Natma Taung National Park (Myanmar) it is one of
the most common epiphytes at 1500–1800 m, but it
was not found to grow as a lithophyte (M. Rodda,
pers. obs.).
Studied specimens. Northern Vietnam, Dien
Bien province, Tua Chua district, Sin Chai munici-
pality, 22°03′38′′N, 103°19′56′′E, primary humid
evergreen broad-leaved forest on limestone at 1350–
1500 m, lithophytic pendent undershrub on vertical
shady mossy cliff on top of ridge, not common, 14
December 2010, L. Averyanov et al., CPC 948 (HN,
LE). Northern Vietnam, Son La province, Moc
Chau district, 2016, C. X. Canh, s. n. (LE – photo).
Hoya carnosa (L. f.) R. Br.,
1810, Prodr. Fl. Nov. Holland.: 460; Li et al.,
1995, Fl. China 16: 232; Pham H.H., 2003, Ill. Fl.
Vietnam 2: 747, g. 6990; Tran T.B., 2005, Check-
list Pl. Sp. Vietnam 3: 66.
≡ Asclepias carnosa L. f., 1782, Suppl. Pl.: 170;
Sims, 1804, Bot. Mag. 21, tab. 788.
Described from China (“Habitat in China”).
Type (“LINN 310.43”) – LINN.
= Stapelia chinensis Lour., 1790, Fl. Cochin-
chin.: 165.
Fig. 3D–F.
Vernacular name in Vietnam. Cẩm cù lý hương
sao.
Habitat, phenology and conservation status.
Semi-woody epiphytic creeping vine to 3 m long.
Flowers white with pink-purple centre, very
fragrant. Primary and secondary broad-leaved
evergreen and semideciduous dry forests on any
kind of rocks, but preferably on rocky limestone,
often near mountaintops, 500–900 m. Fl. March –
April. Occasional. Estimated IUCN Red List
status – LC.
Distribution. Laos (Houphan and Vientiane
provinces), Vietnam (Hoa Binh, Quang Binh, Quang
Ninh, Quang Tri, Lam Dong, Ba Ria – Vung Tau
provinces). India, China, Taiwan, Japan.
Notes. This is the rst record for Laos although
the species is widely distributed in mainland tropical
Asia.
Studied specimens. Northern Laos, Houphan
province, Hem district, Khon Ngua village,
19°55′53.2′′N, 103°16′24.2′′E, secondary broad-
leaved evergreen open dry forest with bamboo on
limestone, 700–950 m, epiphytic and lithophytic
creeping vine 2–3 m long on very steep rocky slope,
owers fragrant, white, with reddish disk, common,
15 April 2015, N. T. Hiep et al., LA-VN 1491 (FOF,
LE – photo). Central Laos, Vientiane province,
Vang Vieng district, Phol Xai village, about 8 km to
the W of Vang Vieng town, Phar Poon Mt., around
point 18°56′11.5′′N, 102°20′05.0′′E, dry broad-
leaved primary and secondary evergreen forest on
limestone, semi-woody epiphytic and lithophytic
vine 4 m long at elevation 800–900 m, owers light
yellowish to almost white, center pink-purple, no
common, 15 March 2013, N. T. Hiep et al., LA-VN
439 (FOF, LE). Central Laos, Vientiane province,
Vang Vieng district, Phol Xai village, about 8 km to
the W of Vang Vieng town, Phar Poon Mt., around
point 18°56′11.5′′N, 102°20′05.0′′E, dry broad-
leaved primary and secondary evergreen forest
limestone, semi-woody epiphytic vine 5 m long on
rocky mountaintops at elevation 800–900 m, very
common, 15 March 2013, N. T. Hiep et al., LA-VN
458 (FOF, LE). Central Laos, Vientiane province,
Vang Vieng district, Na Po village, about 12 km
to the W of Vang Vieng town, Pa Nang Oua Mt.,
18°55′44.9′′N, 102°20′20.1′′E, dry broad-leaved
primary and secondary evergreen and semideciduous
forest on limestone at 600–900 m, semi-woody
epiphytic creeping vine 1–2 m long, owers white
with pink-purple center, very fragrant, occasional,
17 March 2013, N. T. Hiep et al., LA-VN 544 (FOF,
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
111
Fig. 3. Hoya burmanica Rolfe: A–C (C. X. Canh, s. n., photos by C. X. Canh). H. carnosa L. f.) R. Br.: D–F (D, F –
LA-VN 544, photo V. T. Pham; E – LA-VN 1491, photo L. Averyanov). H. chinghungensis (Tsiang et P. T. Li) M. G.
Gilbert, P. T. Li et W. D. Stevens: G–I (C. X. Canh, s. n., photos by C. X. Canh).
Turczaninowia 20 (3): 103–147 (2017)
112
LE). Northern Vietnam, Hoa Binh province, Lac
Son district, Tu Do municipality, Mon village,
around point 20°25′29′′N, 105°19′3′′E, primary
broad-leaved forest on limestone at 500–700 m,
semi-woody vine, occasional, 25 March 2011, N. Q.
Hieu et al., CPC 1592d, . et coll. under cultivation at
May 2014, owers very fragrant, white, corona pink
(LE). Northern Vietnam, Quang Binh province,
Minh Hoa district, Thuong Hoa municipality,
17°41′28′′N, 105°53′42.7′′E, rocky slope of
limestone mountains, in primary closed evergreen
broad-leaved lowland forests at 582 m, semi-woody
vine to 3 m long on mossy exposed rock, owers
white, light pinkish, common, 5 August 2011, N. T.
Hiep et al., CPC 3959 (LE). Northern Vietnam,
Quang Ninh province, Ha Long Bay, 20○54´N,
107○08´E, secondary limestone forest at 0–100 m,
epiphyte and lithophyte with white latex, corona
center purple, common, 8 July 2003, P. V. The,
N. X. Tam, NTH 5749 (HN). Central Vietnam,
Quang Tri province, Huong Hoa district, Huong
Viet, Sa Duong, Sa Lit River, 16º51´N, 106º34´E,
at 650 m, vine 3 m long, 1 April 2006, N. Tap, N. V.
Trai, HLF 6420 (HN, LE).
Hoya chinghungensis (Tsiang et P. T. Li) M. G.
Gilbert, P. T. Li et W. D. Stevens,
1995, Novon 5, 1: 9; Li et al., 1995, Fl. China
16: 236.
≡ Dischidia chinghungensis Tsiang et P. T. Li,
1974, Acta Phytotax. Sin. 12, 1: 130, pl. 31.
Fig. 3G–I.
Described (Tsiang, Li, 1974) from southern Chi-
na (“China, Yunnan, che-li HGsien, Meng soong,
Dah-Meng-Lung, 1900 m”). Type (“Sep. 1936,
C. W. Wang 78311”) – IBSC (holotype), A (isotype).
Vernacular name in Vietnam. Cẩm cù hoa tán.
Habitat, phenology and conservation status.
Humus epiphytic or occasionally lithophytic un-
dershrub with arching and pendulous shoots to 2
m long. Primary broad-leaved evergreen forests on
any kind of soils, but preferably on rocky limestone,
commonly on mountaintops, 700–1500 m. Fl. April
– August. Locally common. Estimated IUCN Red
List status – VU.
Distribution. Laos (Vientiane province), Viet-
nam (Dien Bien, Ha Giang, Lai Chau and Son La
provinces). China, Thailand.
Notes. This is the rst record of this rare species
for the ora of Laos and Vietnam. It is part of a
group of rather similar species including Hoya
dickasoniana P. T. Li (Li, 1994), H. weebella
Kloppenb. (Kloppenburg, 2005), H. lanceolata
D. Don (Don, 1825), H. vaccinioides Hook. f.
(Hooker, 1883), H. engleriana Hosseus (Hosseus,
1907) and H. kingdonwardii P. T. Li (Li, 1994)
that have not been worked out yet but appear to
have very similar ower morphology, but a few
taxa can be separated based on lamina shape.
Hoya chinghungensis is the only species in the
complex bearing almost round leaves. In Laos and
Vietnam H. chinghungensis is a very sensitive,
highly endangered element of the fast decreasing
primary woods and desire status of vulnerable.
The collecting as ornamental plant due to market
demands is additional factor of its extinction.
Studied specimens. Central Laos, Vientiane
province, Kasi district, Thong Mout village, Num
Pong Mt., 19°21´46.9´´N, 102°09´29.8´´E, pri-
mary and secondary broad-leaved evergreen for-
est on steep shale slopes along stream at about
900 m, creeping epiphytic vine to 2 m long on tall
tree, not common, 22 March 2013, L. Averyanov,
N. S. Khang, S. Lorphengsy, LA-VN 728 (LE, FOF,
HNL). Northern Vietnam, Dien Bien province, Tua
Chua district, Sin Chai municipality, 22°03´38´´N,
103°19´56´´E, primary humid evergreen broad-
leaved forest on very steep rocky slopes and on
tops of remnant mountain composed with highly
eroded marble-like solid crystalline limestone at
1350–1500 m, creeping pendent epiphyte on old
mossy tree on top of ridge, locally common, 14 De-
cember 2010, L. Averyanov et al., CPC 951 (LE).
Northern Vietnam, Dien Bien province, Muong
Cha district, Hua Ngai municipality, Ha La Chu vil-
lage, 21°53´46´´N, 103°10´17´´E, highly degraded
primary evergreen broad-leaved humid forest on
very steep slopes of remnant mountains composed
with solid limestone at 1100–400 m, epiphyte on tall
mossy tree, common, 7 April 2011, L. Averyanov et
al., CPC 2049a (LE). Northern Vietnam, Ha Giang
province, Vi Xuyen district, Tung Ba municipality,
Khau Ca nature reserve, primary broad-leaved hu-
mid evergreen forest on limestone at 700–1150 m,
22°50´39.4´´N, 105°07´50.3´´E, epiphytic liana, 80
cm in long, ower white, 8 May 2015, N. Q. Hieu et
al., CPC 7738 (LE). Northern Vietnam, Lai Chau
province, Sin Ho district, Phin Ho municipality, Ta
Genh village, 22°28´26´´N, 103°16´31´´E, 1285 m,
upper slopes and ridges of limestone mountains, ep-
iphyte, rare, June 2006, P. K. Loc et al., HAL 8771
(HN, LE, MO). Northern Vietnam, Son La prov-
ince, Mai Son district, Chieng Kheo commune, 2
May 2011, C. X. Canh s. n. (LE – photos).
Hoya crassipetiolata Aver., V. T. Pham et T. A.
Le, sp. nov.
Fig. 4, 5.
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
113
Type (“15 July 2016, L. Averyanov, T. Maisak,
CPC 2049a”) – LE (holotype, isotypes), herbarium
specimen prepared from cultivated plant collected
in N. Vietnam (“Dien Bien province, Muong Cha
district, Hua Ngai Municipality, Ha La Chu village,
around point 21°53´46´´N, 103°10´17´´E, primary
evergreen broad-leaved humid forest on very steep
slopes of remnant mountains composed with solid
limestone at elevations 1100–1400 m a. s. l., epi-
phyte on tall mossy trees, common, 7 April 2011,
L. Averyanov et al., CPC 2049”). Plate: digital Viet-
namese ora 0257/CPC 2049a, g. 5.
Etymology. Species name refers to the remark-
ably thick leaf petiole.
Vernacular name in Vietnam. Cẩm cù đá.
Description. Epiphytic and lithophytic vine with
milky latex (1.5)2–4(6) m long. Stem dull green
to dull pale brownish-grey, slender, wiry, exuose,
terete, slightly thickened at nodes, (1.6)2–2.8(3.2)
mm in diam., glabrous, twining or climbing by
many adventitious roots; leafy almost throughout;
internodes (5)18–15(18) cm long. Leaves glabrous,
decussate, petiolate. Petiole very thick (often twice
thicker than stem), dark green when young, later
dull brownish-grey, barky, usually strongly curved
or twisted, (0.8)1–1.8(2) cm long, (2.8)3–4.5(5)
mm in diam., semi terete in cross section, shallowly
broadly grooved adaxially; young petioles at apex
with pair of small whitish colleters, later maturing
into prominent hemispheric barky callus (1)1.5–2
mm tall. Leaf blade eshy coriaceous, rhomboid
elliptic, (4.5)5.5–9.5(10.5) cm long, (2.2)2.5–4(4.5)
cm wide, slightly curved, shortly acuminate at base
and apex, uniform green or green/white tessellated
above, light pale green to almost white below,
adaxially with distinct dark green midvein and 3–5
pairs of irregularly arching and branching lateral
veins, abaxial surface with prominent green midrib
and hardly visible lateral veins. Inorescence an
extra-axillary many-owered umbel; peduncle
rather stout, spreading or pendulous, cylindrical,
(2)3–6(8) cm long, (2)3–4(4.5) mm in diam., dull
to dark greenish or brownish, glabrous; rachis
swelling, perennial, growing up to 10(15) mm
long and 5 mm in diam., forming ower sets
time to time during 2–3 (or more) years; pedicels
greenish-white, cylindrical, slender, (1.6)1.8–2(2.2)
cm long, 1–1.2 mm in diam., glabrous, sometime
very nely granulose. Flowers odorless. Calyx
at, (4.4)4.6–4.8(5) mm in diam., glabrous or very
nely granulose, of 5 sepals almost free at base,
sepals light pale dull olive-greenish, triangular
ovate, obtuse to blunt, (1.4)1.5–1.6(1.8) mm long,
(1.2)1.3–1.4(1.5) mm wide near base. Corolla of 5
petals, (1.5)1.6–1.7(1.8) cm in diam. when attened,
white, with greenish, pinkish or almost white lobes;
petals strongly recurved, rhomboid, tube 1.8–2.2
mm long, free part (5.5)6–7(7.5) mm long, (4.2)4.5–
4.8(5) mm wide at middle, straight along margin,
triangular acute at apex, inside densely papillose at
the base, glossy glabrous in apical half, glabrous
outside. Corona glossy, uniform pure white or with
light pink tinge, of 5 lobes, (1.9)2–2.2(2.3) mm tall,
(7.8)8–8.8(9) mm in diam., grooved between lobes;
lobes obliquely ellipsoid in outline, at and little
concave above, (3.6)3.8–4(4.1) mm long, (1.8)2–
2.2(2.3) mm wide, at the base roundish with revolute
margins, outer and inner processes obtuse, short,
not reaching the style head apex. Style head discoid
oblate, (1)1.1–1.2(1.3) mm tall, (2.1)2.2–2.4(2.5)
in diam.; anther appendages yellowish; corpuscula
chestnut-brown. Pollinarium: corpusculum narrowly
rhomboid, angled, 0.2–0.25 mm long, 0.1–0.15 mm
wide; translators very short, about 0.05 mm long;
pollinia oblong, (0.4)0.5(0.6) mm long, 0.1–0.15
mm wide, yellow; germinating crest very narrow,
light yellowish, hyaline, extending from translator to
pollinium apex. Carpels 2, free, half bottle-shaped,
densely connivent each other, 1.4–1.6 mm tall,
0.6–0.7 mm wide at the base, articulated apically to
white, oblate stigma head, (0.7)0.8–0.9(1) mm tall,
2.2–2.4 mm in diam.
Habitat, phenology and conservation status.
Creeping epiphytic and lithophytic herbaceous to
semi-woody vine to 6 m long. Secondary evergreen
broad-leaved lowland forests on sandy soils along
seashore and primary broad-leaved evergreen
forests on rocky karstic limestone, often on steep
slopes and cliffs near mountaintops, 10–1400 m. Fl.
May – August. Locally common. Estimated IUCN
Red List status – DD.
Distribution. Vietnam (Bac Kan, Dien Bien,
Khanh Hoa, Quang Binh and Quang Tri provinces).
Endemic.
Notes. This new species is rather similar in leaf
and ower morphology to Hoya hainanensis Merr.
(Merrill, 1923) because both species have rhomboid
elliptic leaves with a decussate base, reexed corol-
la and ellipsoid corona lobes. The two species can
be separated by the upper surface of the corona lobe
that is at in H. crassipetiolata (vs. sunken) and the
inner process of the corona lobe that is obtuse, short
(vs. apiculate and recurved upwards). In its oral
morphology H. crassipetiolata is also very similar
to H. pachyclada Kerr (Kerr, 1939) widely distribut-
ed in Thailand and Cambodia. However, it is totally
Turczaninowia 20 (3): 103–147 (2017)
114
Fig. 4. Hoya crassipetiolata Aver. et V. T. Pham. Drawn from the type (CPC 2049a), by L. Averyanov and T. Maisak.
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
115
Fig. 5. Hoya crassipetiolata Aver. et V. T. Pham. Digital Vietnamese ora 0257/CPC 2049a. Photos, correction and
design by L. Averyanov and T. Maisak.
Turczaninowia 20 (3): 103–147 (2017)
116
different in its vegetative habit. Described plant is
slender herbaceous or semi lignied vine (not un-
dershrub with rather robust stems), glabrous in all
parts (vs. sparsely pubescent leaves, peduncle, pedi-
cels and calyx), coriaceous (not eshy) leaves and
glabrous corona base (not densely hairy with long
hairs). It may be also close to H. verticillata (Vahl)
G. Don s. l., including H. acuta Haw. (Haworth,
1821) and H. parasitica Wall. ex Wight (Wight,
1834) widely distributed in tropical Asia, but well
differs in rather sparse, not many-owered umbels,
larger owers with strongly recurved broad petals,
broadly ellipsoid corolla lobes with rather obtuse
outer angle and prominent, irregularly branching
secondary veins on leaf blade. The species super-
cially resembles the type specimens of H. oblonga-
cutifolia Costantin (Costantin, 1912) [P00639820,
P05207933, P00639821, P00639822] in character
of leaf size and venation, but quite differs in distinct
prominent secondary veins (hardly visible in leaves
of H. oblongacutifolia), glabrous pedicels (not
hairy) and bigger ower with corolla 1.5–1.6 cm
in diameter (not about 1.2 cm across recorded for
H. oblongacutifolia). The new species may be also
easily distinguished by its unusually thick petioles
(twice thicker as stem) and usually quite distinct
green/white tessellation of adaxial surface of leaf
blade. The species is easily cultivated and may be
recommended as a fast growing ornamental plant.
A collection from Khanh Hoa province (2014,
N. V. Canh s. n.) is intermediate between H. cras-
sipetiolata and H. hainanensis; the inner process of
the corona lobe is acute (as in H. hainanensis), but
the corona lobes are at (as in H. crassipetiolata).
Studied specimens (paratypes). Northern Vi-
etnam, Bac Kan province, Cho Don district, Ban
Thi municipality, Phia Khao village, Lung Li valley,
22º16’´10’’N, 105º31’01’’E, Cot Moc Mt., 800–900
m, primary broad-leaved evergreen closed forest
on limestone ridge, herbaceous or hemi-woody
vine 4–6 m long, owers white, disc light pink, not
common, 23 May 2004, L. Averyanov al., HAL
4836 (HN, LE). Northern Vietnam, Quang Binh
province, Minh Hoa district., Thuong Hoa com-
mune, Ban On village, 17°40´21´´N, 105°57´59´´E,
300–350 m, primary evergreen broad-leaved forests
on limestone ridge, epiphyte, not common, 27 July
2011, P. K. Loc et al., CPC 5197 (HNU, LE – pho-
to). Southern Vietnam, Khanh Hoa province, Nha
Trang City area, Vung Ro Bay, 2014, N. V. Canh
s. n. (LE –photos). Southern Vietnam, Quang Tri
province, Hai Lang district, Hai Duong commune,
16°43´28.84´´N, 107°20´51.86´´E, 10–50 m, sec-
ondary evergreen broad-leaved forest on sandy
swampy lowland near sea shore, creeping epiphyte
to 5 m long, umbel of 11–28 owers, owers white
mixed with light-yellow and light purple in center,
fragrant, 5 August 2013, L. T. Anh, PVT QT 009-
2013 (HN, HNU, LE, LE – photos).
Hoya erythrina Rintz,
1978, Malayan Nat. Journ. 30, 3–4: 501, g. 17.
Fig. 6A–C.
Described from southern part of Peninsular
Malaysia (“Endemic to Malaya, in hill forests
in Pahang and Selangor from 400–700 m and at
Bertam, Ulu Kelantan; common but not abundant
along rivers on both sides of The Gap”). Type
(“Malaysia, Pahang, Sungai Teranum, 600 m, alt.
25–9–1976, Rintz 117”) – L [L0004323] (holotype).
Vernacular name in Vietnam. Cẩm cù san hô.
Habitat, phenology and conservation status.
Creeping epiphytic and lithophytic herbaceous or
semi-woody vine to 5 m long. Primary and secondary
broad-leaved evergreen forests, particularly on
granite outcrops in humid places along streams,
300–500 m. Fl. November, occasionally all around
the year. Locally common. Estimated IUCN Red
List status – DD.
Distribution. Vietnam (Dak Lak and Khanh Hoa
provinces). Thailand, Southern part of Peninsular
Malaysia (Kelantan, Pahang and Selangor provinc-
es).Notes. This is a remarkable discovery of a rare
species regarded earlier as occurring in peninsular
Malaysia and Thailand only. The distance between
its recorded locations in southern Vietnam and
the locus classicus in Malaysia exceeds 1400 km.
H. erythrina is widely cultivated as an ornamental
plant. Its owers vary in color from white and yel-
lowish to pink.
Studied specimens. Southern Vietnam, Dak
Lak province, Chu Yang Sin Mountains, 2014, N. V.
Canh s. n. (LE – photos). Southern Vietnam, Dak
Lak province, Krong Bong district, 12°28´17’’N,
18°02´45’’E, 400–500 m, secondary evergreen for-
est on granite outcrops, epiphytic and lithophytic
creeping vine to 5 m long in humid places along
stream, owers yellowish, common in Krong Bong
district near Chu Yang Sin National Park and in
M´Dak district near Ea So Natural Reserve, herbar-
ium specimen prepared from cultivated plant col-
lected from the wild, 18 November 2015, P. D. Q.
Vuong, PVT DL 008-2015 (HN, LE, LE – photo).
Southern Vietnam, Khanh Hoa province, Khanh
Son district, en route from Cam Ran to Khanh Son,
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
117
Fig. 6. Hoya erythrina Rintz: A–C (PVT DL 008-2015, photo by V. K. Nguyen). H. erythrostemma Kerr: D–F (N. V.
Canh s. n., 2014, photo by N. V. Canh). H. globulosa Hook. f.: G–I (LA-VN 1117, photo of N. S. Khang).
Turczaninowia 20 (3): 103–147 (2017)
118
950 m, 19 May 1998, P.C. Boyce 1322, cultivated at
the Royal Botanic Gardens Kew, acc. no. 19982780,
31 July 2012, s. coll. (K [K000397245]).
Hoya erythrostemma Kerr,
1939, Bull. Misc. Inf. Kew. 8: 460; id., 1951. Fl.
Siamensis Enum. 3, 1: 36.
Fig. 6D–F.
Described from peninsular Thailand. Lectotype
(“Thailand, Tasan, C. B. Kloss 6909”) – K
[K000895112], lectotype designated by Rodda et al.
(2014).
Habitat, phenology and conservation status.
Creeping epiphytic herbaceous or semi-woody
vine to 5 m long. Primary and secondary broad-
leaved evergreen lowland forests on alluvial soils.
Fl. October – November, occasionally year round.
Rare. Estimated IUCN Red List status – DD.
Distribution. Vietnam (Dak Lak province).
Thailand.
Notes. H. erythrostemma was thought to be en-
demic to Thailand (Rodda et al., 2014) and with its
discovery in Vietnam in Dak Lak province its range
is extended about 500 km further eastwards.
Studied specimens. Southern Vietnam, Dak
Lak province, Ea Kar district, Ea So nature reserve,
primary and secondary lowland broad-leaved ever-
green forest, N. V. Canh s. n., 2014 (LE – photos).
Hoya fungii Merr.,
1934, Lingnan Sci. Journ. 13: 68; Li et al., 1995,
Fl. China 16: 233.
Fig. 7.
Described from S China. Type (“Hainan: Chim
Shan, Fan Maan Ts´uen and vicinity, Ling shui
(Ling-tui) district, growing on mountain side;
semi-woody; 6 m.; . petals white center red; frag.,
Fung, H., 20137, May 3–20, 1932”), syntypes – A
[A00076413], IBSC, PE [PE1642209-00029475,
PE1642208-00029476]).
Vernacular name in Vietnam. Cẩm cù nấm.
Habitat, phenology and conservation status.
Epiphytic and occasionally lithophytic semi-woody
vine to 10 m long. Primary and secondary broad-
leaved evergreen forests on any kind of mother
rocks, but preferably on rocky limestone, often on
tall trees along streams and small rivers, 0–1200 m.
Fl. March – August, December. Locally common.
Estimated IUCN Red List status – DD.
Distribution. Laos (Bolikhamsai, Champasak
and Louangphrabang provinces), Vietnam (Dak
Lak, Hai Phong, Hoa Binh, Quang Binh and Quang
Tri provinces). S China (Guangdong, Guangxi,
Hainan, Yunnan).
Notes. This species is new for the oras of Laos
and Vietnam. It is similar in corolla and corona mor-
phology to H. bonii Costantin (Costantin, 1912) and
H. carnosa (L. f.) R. Br. (Brown, 1810). However,
H. fungii differs from H. bonii in oblong elliptic
(not cordate) glabrous leaves (young leaves and
stems may be pubescent), which are bigger, longer
and having distinct venation. The calyx lobes of
H. fungii are lanceolate and pubescent while H. car-
nosa has shorter triangular calyx lobes. According
to visual not documented observations of Mr Nguy-
en Van Canh, this species is also common in some
areas of Dak Lak province. The plant is fast growing
vine desirable for cultivation as ornamental plant.
Studied specimens. Northern Laos, Louang-
phrabang province, Pon Xay district, Houay Man
village, Phou Pak Sang Mountain, 19°59’03.8’’N,
102°25’09.0’’E, degraded primary evergreen and
semideciduous forest on limestone at 1000–1150,
creeping semi-woody epiphytic and lithophytic
vine to 5 m long on mountain top, owers pinkish,
common, 4 April 2017, L. Averyanov et al., LA-VN
2034 (FOF, LE). Northern Laos, Louangphrabang
province, Pon Xay district, between Houay Man
and Nam Bo villages, Phou Hua Ben Toc Mountain,
19°57’33.1’’N, 102°25’25.8’’E, degraded primary
evergreen and semideciduous forest on limestone
at 500–650 m, creeping epiphyte and lithophyte
vine 4–6 m long on open mossy rocky mountain
top, owers pink, corona center purple, locally
common, 5 April 2017, L. Averyanov et al., LA-
VN 2117 (FOF, LE). Central Laos, Bolikhamsai
province, Thaphabat district, Nam Bon village, Phou
Khao Khouay national park, Tad Xai Waterfall,
18°27’25.9’’N, 103°08’17.5’’E, degraded primary
and secondary evergreen dry forest along river on
eroded sandstone at 340 m, semi-woody epiphytic
and lithophytic vine to 10 m long in rather open
place, owers sweet-spicy scented, white, center of
corona pink, common, 11 April 2017, L. Averyanov
et al., LA-VN 2193 (LE). Southern Laos, Champa-
sak province, Paksong, Bolaven Plateau, 5 Km south
of Ban Phupakor, primary forest at the edge of prec-
ipice, epiphyte, sap transparent, originally collected
30 October 2015, M. Rodda, L. Tan, L. Guglielmone
et al., MR 1739, owered in cultivation, Singapore
Botanic Gardens, 21 September 2016, M. Rodda,
MR 1739 (SING). Northern Vietnam, Quang Binh
province, Minh Hoa district, Hoa Son municipal-
ity, Ka Xai valley, 17°42´10.4´´N, 105°47´57.3´´E,
primary logged closed evergreen broad-leaved for-
est and woodland on wet shale valley at about 402
m, epiphyte semi-woody vine; owers white, or-
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
119
Fig. 7. Hoya fungii Merr. Digital Vietnamese ora 0262/PVT QT 011-2016. Photos by T. A. Le, correction and design
by L. Averyanov.
Turczaninowia 20 (3): 103–147 (2017)
120
ange at center, peduncle purplish, common, 14 Au-
gust 2011, N. T. Hiep, N. Q. Hieu, N. V. Tap et al.,
CPC 4196 (CPC Herbarium). Southern Vietnam,
Dak Lak province, Chu Yang Sin Mountains, 2015,
N. V. Canh s. n. (LE – photos). Southern Vietnam,
Quang Tri province, sine loc., 2014, N. V. Canh
s. n. (LE – photos). Southern Vietnam, Quang Tri
province, Huong Hoa district, Huong Son commu-
nity, 16°45´N, 106°36´E, along stream of second-
ary evergreen forest at 600 m, 24 December 2013,
L. T. Anh, PVT QT 011-2016 (HN, LE, HNU).
Plate: digital Vietnamese ora 0262/PVT QT 011-
2016, g. 7.
Hoya globulosa Hook. f.,
1882, Gard. Chron. n. s. 17: 732, 741, g. 115;
Costantin, 1912, Fl. Indo-Chine 4: 140; Pham H. H.,
2003, Ill. Fl. Vietnam 2: 748, g. 6995; Tran T. B.,
2005, Checklist Pl. Sp. Vietnam 3: 67.
Fig. 6G–I.
Described from NE. India (“Sikkim Himalaya”).
Lectotype – icon: “Hoya globulosa” (Gard.
Chronicle, 1882, n. s. 17: 741, g. 115), lectotype
designated by Jagtap and Singh (1999: 100).
= H. villosa Costantin, 1912, l.c.: 137, syn. nov.
Vernacular name in Vietnam. Cẩm cù cầu.
Habitat, phenology and conservation status.
Epiphytic and lithophytic creeping vine to 3 m long.
Primary and secondary broad-leaved evergreen
forests on any kind of mother rocks, often on karstic
limestone, 800–950 m. Fl. March – April. Locally
common. Estimated IUCN Red List status – DD.
Distribution. Laos (Houphan and
Louangphrabang provinces), Vietnam (Ha Giang
province). NE. India.
Collections cited below present new record of
this species for the ora of Laos.
Studied specimens. Northern Laos, Houphan
province, Viengxay district, Vieng Xai village,
20°23´41.3´´N, 104°13´44.5´´E, primary and
secondary broad-leaved evergreen dry forest on
limestone at 800–950 m, semi-woody vine 2–3 m
long in rather open, exposed rocks, owers white,
sweet fragrant, corona inside purple, common, 7
April 2015, N. T. Hiep et al., LA-VN 1117 (FOF,
HNL, LE). Northern Laos, Louangphrabang
province, Muang Ngoi, disturbed primary forest on
limestone, 350–400 m, terrestrial climber 3–4 m long,
C. Puglisi, M. Rodda, K. Souvannakhoummane,
LAOS 75 (SING). Northern Vietnam, Ha Giang
province, Vi Xuyen district, Tung Ba municipality,
Khau Ca nature reserve, primary broad-leaved
humid evergreen forest on limestone at 700–1150
m, 22°50´43.9´´N, 105°07´18.5´´E, vine 3–5 m
long, common, 9 May 2015, N. Q. Hieu et al., CPC
7822 (LE).
Hoya grifthii Hook. f.,
1883, Fl. Brit. India 4: 59; Li et al., 1995, Fl.
China 16: 235.
Fig. 8A–C.
Described from NE. India based on two syntypes
(“Khasia Mts., Grifth; Nowgong, alt. 2–4000 ft.,
J. D. H. et T. T.”). Lectotype (“India, East Bengal,
s. d., Grifth 3794”) – K [K001045835], lectotype
here designated.
Vernacular name in Vietnam. Cẩm cù khủng
long.
Habitat, phenology and conservation status.
Creeping epiphytic vine. Primary and secondary
broad-leaved evergreen humid mountain forests,
often with bamboo, on any kind of mother rocks,
900–1400 m. Fl. April – May, August – December.
Not common. Estimated IUCN Red List status –
DD.
Distribution. Laos (Louang Namtha province),
Vietnam (Dien Bien and Quang Ninh provinces).
NE India, S China (Guangdong, Guangxi, Guizhou,
Hainan, Yunnan), Thailand.
Note. The discovery of this rare species in
highland areas of northern Vietnam and Laos is not
much surprising. It was known before in NE India,
S China and Thailand. Records listed here are the
rst for the ora of Vietnam. The species has large
attractive owers and may be recommended for
cultivation as a fast, rather cool growing ornamental
vine.
Studied specimens. Northern Laos, originally
collected in Louang Namtha province, Louang
Namtha, along the road to Muang Sing, 1000 m,
evergreen broad-leaved forest mixed with bamboo
on steep terrain, cultivated at the Singapore
Botanic Gardens, vouchered as M. Rodda, MR
415 on 17 August 2013. Northern Vietnam, Dien
Bien province, Muong Cha district, Hua Ngai
municipality, Ha La Chu village, 21°53´46´´N,
103°10´17´´E, highly degraded primary evergreen
broad-leaved humid forest on limestone, 1100–
1400 m, creeping epiphyte on tall mossy tree, 7
April 2011, L. Averyanov et al., CPC 2049b (LE).
Northern Vietnam, Quang Ninh province, with
no exact locality, 2013, N. V. Canh s. n. (LE –
photos). Northern Vietnam, Quang Ninh province,
Hoanh Bo district, Ky Thuong municipality, 900
m, 21°12´N, 107°09´E, primary and secondary
evergreen broad-leaved closed forest and bamboo-
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
121
Fig. 8. Hoya grifthii Hook. f. – A–C (CPC 2049b, photos by L. Averyanov). H. lanceolata D. Don: D–F (12 July
1999, N. L. Orlov s. n., photos by N. L. Orlov). H. linearis Wall. ex D. Don: G–I (HAL 10694, photos by L. Avery-
anov).
Turczaninowia 20 (3): 103–147 (2017)
122
mixed forest, along stream, epiphytic vine,
occasional, 17 August 2015, N. V. Canh, N. T. Nhat,
PVT QN 013-2015 (HN, LE).
Hoya hainanensis Merr.,
1923, Philipp. Journ. Sci. 23: 263.
Fig. 9.
Described from China, Hainan (“China, Hainan,
S slope of ve nger mountains, growing on trunk
of tree …”). Type (“May 1922, McClure, F.A.
9759”), syntypes – A [A00076415, A00076416],
IBSC [IBSC005678], MO [MO-024520], UC
[UC366286], US [US00026725].
Description. Lithophytic vine with milky latex
to 5 m long. Stems slender, rooting at nodes and
internodes, green and hairy when young, light grey,
glabrous when old, terete, 1.6–1.8 mm in diam.,
internodes up to 25 cm long. Leaves petiolate;
petiole stout, twisted, grooved, sparsely hairy, 4–6
mm long, 2–2.5 mm in diam. Leaf blade elliptic to
oblanceolate, more or less eshy, 9–11 cm long,
4–5 cm in wide, slightly curved, attenuate at base
and apex, above dark green, below light green, with
distinct reticulate nerves on adaxial surface, hardly
visible abaxially except keeled midrib, indistinct
secondary veins about 4–6 pairs, extended to
margin, few short hairs visible under magnication
on midrib of both surfaces. Inorescences round
umbel extra-axillary, commonly of 8–30 owers;
peduncle cylindrical, stout, swollen at base and
apex, hairy, 13–15 cm long, 1.5–4 mm in diam.,
green to dark green with some dirty purple marks;
pedicels white speckled with purple, slender, 1.8–2
cm long, about 1 mm in diam. Flowers pure white
with red–purple center. Calix of 5 segments; sepals
triangular, acute at apex, about 1.2–1.4 mm long and
wide. Corolla 5-lobed, about 1.4 cm in diam.; lobes
eshy, ovate, acute, adaxially pubescent, pure white,
abaxially glabrous, dull white-purplish, 6 mm long,
3.8 mm wide, slightly reexed, margin revolute.
Corona white with red–purple center, of 5 segments,
about 2.2–2.4 mm tall and 7–7.2 mm in diameter,
sunken in surface; segments glossy, almost white
with red–purple inner angle, outer angle acute and
curved, inner angle apiculate, 2.2–2.4 mm tall, 2.1–
2.2 mm wide. Gynostegium bears on top 5 pollinaria
covered by membranous yellowish anther caps.
Pollinarium of two pollinia connected by two short
translators; corpusculum about 0.18 mm long, 0.09
mm wide, chestnut, narrowly rhomboid, angled,
acute; pollinium oblong, bright yellow, about 0.6–
0.7 mm long, 0.2–0.24 mm wide, 0.07–0.09 mm
thick; with germinating crested extending from
translator to pollinium apex. Carpels 2, free, half
bottle shaped, about 1.5 mm tall, 0.6 mm in diam.,
densely connivent each other, light green–purplish,
apex shortly cuspidate and joined to stigma head
bottom.
Habitat, phenology and conservation status.
Lithophytic and occasionally epiphytic creeping
vine. Primary evergreen broad-leaved forests,
often on granite outcrops along streams, 800 m. Fl.
January – February. Locally common. Estimated
IUCN Red List status – DD.
Distribution. Vietnam (Dak Lak province).
S. China (Hainan).
Notes. H. hainanensis was only known from
Hainan Island. Its discovery in southern Vietnam
considerably extends its known distribution area.
This species is known insufciently in the ora
of Vietnam; hence we provide here its description
based on Vietnamese material.
Studied specimens. Southern Vietnam, Dak
Lak province, M´Drak district, Chu Mu Mountain,
around point 12°41´N, 108°54´E, primary evergreen
forest, January 2016, N. V. Canh, L. T. N. Thanh,
FOP/02/2016/Hoya (HNIP).
Hoya lanceolata D. Don,
1825, Prodr. Fl. Nepal.: 130.
Fig. 8D–F.
Described from Nepal (“Hab. In Nepalia”). Lec-
totype (“Wallich”) – BM [BM000521681], isolec-
totypes – BM [BM000574470], FI [FI009184]; lec-
totype here designated.
Habitat, phenology and conservation status.
Epiphytic herb or undershrub with creeping or
spreading shoots to 0.5 m long. Primary and
secondary broad-leaved evergreen submontane
forests, 1200–1300 m. Fl. June – July. Very rare.
Estimated IUCN Red List status – DD.
Distribution. Vietnam (Lai Chau province). Ne-
pal, NE India, Myanmar, N Thailand.
Notes. Very rare ornamental plant closely related
to the widely cultivated H. bella Hook. (Hooker,
1848, t. 4402), which is sometimes regarded as a
subspecies of H. lanceolata D. Don subsp. bella
(Hook.) D. H. Kent (Kent, 1981).
Studied specimens. Northern Vietnam, Lai
Chau province, Than Uyen district, 1250 m, 12 July
1999, N. L. Orlov s. n. (LE, LE – photos).
Hoya linearis Wall. ex D. Don,
1825, Prodr. Fl. Nepal.: 130; Li et al., 1995, Fl.
China 16: 235.
Fig. 8G–I.
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
123
Fig. 9. Hoya hainanensis Merr. Plate made from FOP/02/2016. Photos, correction and design by N. V. Canh, H. T.
Nguyen and V. T. Pham.
Described from Nepal (“Hab. in Nepalia”). Syn-
types (“Wallich 8155”) – BM, E [E00288750], K
[K001129095; K001129094]
Vernacular name in Vietnam. Cẩm cù rủ.
Habitat, phenology and conservation status.
Branch and trunk epiphyte with pendulous shoots
to 1 m long. Primary and secondary broad-leaved
evergreen humid forests on any kind of mother
Turczaninowia 20 (3): 103–147 (2017)
124
rocks, commonly on old mossy trees on shady steep
slopes along stream canyons, 900–1600(2000)
m. Fl. September – October. Very rare. Estimated
IUCN Red List status – DD.
Distribution. Laos (Vientiane province), Viet-
nam (Lao Cai and Lai Chau province). NE India,
Nepal, Myanmar, SW China (NW Yunnan).
Notes. Easily distinguished species for its long
slender herbaceous drooping shoots bearing densely
hairy, almost terete leaves. Collected in Vietnam by
Poilane as early as 1926 (Poilane 12932), but the
specimen was until recently not identied to species.
Studied specimens. Northern Laos, Vientiane
province, Kasi district, between San and Tham Tai
villages, 19°17’47.9’’N, 102°08’58.9’’E, secondary
broad-leaved evergreen dry forest on limestone
at 900–1000 m, epiphyte on tall mossy tree on
steep shady stream slope, rare, 25 March 2017,
L. Averyanov et al., LA-VN 1623 (LE). Northern
Vietnam, Lai Chau province, Sin Ho district, Ta
Ngao municipality, Hai Ho village, 22º16´09´´N
103º14´34´´E, remnants of primary and second-
ary evergreen closed wet forest on limestone at
1500–1600 m, pendent epiphyte on mossy tree
on very steep rocky wet shady slope, rare, 20 No-
vember 2006, N. T. Hiep, L. Averyanov, P. V. The,
HAL 10051 (HN, LE, MO). Northern Vietnam,
Lai Chau province, Phong Tho district, Sin Suoi
Ho municipality, Sa Ma Pho village, 22°32´26´´N
103°32´05´´E, secondary open evergreen broad-
leaved forest on very steep mountain slopes along
rocky stream valley composed predominantly with
weathered granite at 1000–1100 m, epiphyte with
pendent shoots up to 1 m long on mossy tree along
shady rocky stream valley, rare, 13 December 2006,
N. T. Hiep, L. Averyanov, P. K. Loc et al., HAL
10694 (HN, LE, MO). Northern Vietnam, Lao Cai
province, Sa Pa district, 14 August 1926, E. Poilane
12932 (P [P05207667]).
Hoya lobbii Hook. f.,
1883, Fl. Brit. India 4: 54.
Described from central India (“India, Nowgong,
alt. 1500 ft.”). Lectotype (“T. Lobb s. n.”) – K
[K000873093], lectotype here designated.
Habitat, phenology and conservation status.
Humus epiphytic and lithophytic undershrub. Fl.
November – December. Estimated IUCN Red List
status – DD.
Distribution. Cambodia (Pursat province). In-
dia, Thailand.
Notes. H. lobbii is found in central India and
Thailand and its record in neighbouring Cambodia
is therefore not surprising.
Studied specimens. Western Cambodia, Pursat
province, Veal Viang district, Phnom Samkos wild-
life sanctuary, Yai Mau Shrine area, c. 5 km SW of
Dei Kraham village, 12°12′34.6′′N, 102°53′50.0′′E,
890 m, in primary, evergreen, seasonal hard-wood
forest on sandstone bedrock, evergreen lithophytic
and epiphytic succulent vine, abundant white sap
when cut, leaf blades glossy dark green above, pale
green below, fruits light green, 12 March 2015, F. F.
Merklinger 2015-6 (SING).
Hoya lockii V. T. Pham et Aver.,
2012, Nord. Journ. Bot. 30: 49, g. 1; 2; 3A, B.
= H. poilanei Rodda, Simonsson et T. B. Tran, in
sched. (P).
Described from central Vietnam (“Vietnam:
Thua Thien – Hue province, A Luoi district, Huong
Nguyen municipality, around point 16°06´04´´N,
107°27´55´´E, on tree in pristine primary evergreen
broad-leaved and mixed forest, 1000 m a. s. l.”).
Type (“12 May 2011, L. Averyanov, V. T. Pham,
N. T. Vinh, CPC 3092”) – CPC Herbarium (holo-
type), LE, VNM (isotypes). Plate: digital Vietnam-
ese ora 0176/CPC 3092.
Vernacular name in Vietnam. Cẩm cù lộc.
Habitat, phenology and conservation status.
Humus epiphytic undershrub. Primary evergreen
broad-leaved, mixed and coniferous forests on any
kind of mother rocks, commonly on tall trees in
sunny canopy zones, 500–1200 m. Fl. May – August.
Occasional. Estimated IUCN Red List status – DD.
Distribution. Vietnam (Quang Binh, Quang Tri
and Thua Thien – Hue provinces).
Notes. This local Vietnamese endemic is close to
the widespread species H. multiora Blume (Blume,
1823). According to available collections, it is not
rare in its limited area in central part of Vietnam. Ink
and color illustrations of this species were presented
in early publication (Pham, Averyanov, 2012).
Studied specimens. Northern Vietnam,
Quang Binh province, Minh Hoa district, Hoa
Son municipality, B´Lam Lang limestone mt.,
17°42´15.8´´N, 105°48´24´´E, primary closed ev-
ergreen broad-leaved forest on alluvial valley at
534 m, epiphyte, occasional, 16 August 2011, N.
T. Hiep et al., CPC 4345 (LE, LE – photo), CPC
4383 (LE). Southern Vietnam, Quang Tri prov-
ince, dent du Tigre, epiphyte with milky latex, 1200
m, 1924-5-7, E. Poilane 10301 (P [P00700447,
P00700451]), 1100–1300, 1924-5-8, E. Poilane
10335 (P [P00700450, P00700453]), 11327 (P
[P00700454]). Southern Vietnam, Quang Tri prov-
ince, massif de Dong Che pres de Moi Lanh, 800
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
125
m, epiphyte with milky latex, 1924-5-23, E. Poil-
ane 10548 (P [P00700455, P00700448]. Southern
Vietnam, Thua Thien – Hue province, Nui Bach
Ma, 1000–1200 m, epiphyte, 1939-4-21, E. Poilane
29877 (P [P00700449]). Southern Vietnam, Quang
Tri province, massif de Dong Tri, 950 m, epiphyte,
owers white, 1924-6-17, E. Poilane 11021 (P
[P00700452]). Southern Vietnam, Thua Thien –
Hue province, Bach Ma Mt., 1400 m, epiphyte,
1943-11-15, J. E. Vidal 682a (P [P00700440]).
Southern Vietnam, Thua Thien – Hue province, A
Luoi district, Hong Van municipality, Ta Lo village,
16°23´44´´N, 107°09´15´´E, at 1000–1150 m, sec-
ondary wet closed broad-leaved forest on very steep
mountain slopes and edges of ridges composed with
shale, epiphyte 1–2 m tall, not common, 1 May
2005, L. Averyanov et al., HAL 7708 (LE – photo).
Hoya loyceandrewsiana T. Green,
2008, Fraterna 21, 2: 22; id., 1994, Fraterna 4: 4,
nom. invalid.
Fig. 10A–C.
Described on the base of cultivated plants of un-
known origin (Green, 2008). Type (“USA, Hawaii,
Kaaawa, Green Plant Research Nursery as T. Green
9301 in 1995”) – BISH [BISH1016620] (holotype),
NY [NY00991033] (isotype).
Habitat, phenology and conservation status.
Epiphytic creeping semi-woody vine. Primary and
secondary evergreen broad-leaved lowland forests.
Fl. October – November. Very rare. Estimated IUCN
Red List status – DD.
Distribution. Vietnam (Quang Ngai province).
Endemic?
Notes. H. loyceandrewsiana was described based
on cultivated material of unknown origin. This is the
rst discovery of the species in the wild.
Studied specimens. Southern Vietnam, Quang
Ngai province, without exact locality, 6 June 2016,
N. V. Canh, plant cultivated in private garden in
Buon Ma Thuot City, herbarium specimen prepared
in 12 October 2016 by N. V. Canh, L. Averyanov,
T. Maisak, AL 239 (LE, LE – photos).
Hoya lyi H. Lév.,
1907, Bull. Soc. Bot. France. 54: 369; Rodda,
2012, Edinburgh Journ. Bot. 69: 85.
– H. mekongensis auct. non M. G. Gilbert: Li et
al., 1995.
Fig. 10D–F, 11.
Described from SE. China (“Kouy-Tchéou: en-
vironse de Gan-Pin, 20 septembre 1897: sur parois
des rochers surplombant une dépression en forme
de cirque (L. Martin et Emile Bodinier); Lo-Pié, ro-
cailles prés du marché, 7 octobre 1897 (Léon Mar-
tin et Séguin), n° 1853; Tsien-Sen-Kiao, novembre
1904, n° 1879 (Jean Ly)”). Lectotype (“Guizhou,
Tsien-Sen-Kiao, November 1904, Ly 1879”) – E
[E002794520], lectotype designated by Rodda
(2012).
Vernacular name in Vietnam. Cẩm cù ly.
Habitat, phenology and conservation status.
Epiphyte or lithophyte with creeping shoots to
2 m long. Primary broad-leaved and coniferous
evergreen humid forests on any kind of mother
rocks, 1000–2100 m. Fl. October – November.
Locally common. Estimated IUCN Red List status
– DD.
Distribution. N Laos (Houa Phan and Xiangk-
houang provinces), Vietnam (Ha Giang, Lai Chau,
Lam Dong, Lao Cai, Nghe An, Son La, Thanh Hoa
and Tuyen Quang provinces). S China (Guangxi,
Guizhou, Sichuan, Yunnan).
Notes. This miniature ornamental species may
be easily recognized in nature even in sterile state
by its small oval leaves and dense soft short indu-
mentum on all plant parts. The species was previ-
ously recorded from China, Laos and from Vietnam-
Chinese border (Rodda, 2012). Presently recorded
localities of this species are located almost through-
out all mountain areas of Vietnam, and in Xiangkh-
ouang and Houa Phan provinces of Laos. Cultivated
specimens often develop much larger leaves to 18
cm long (vs. 2–4 cm in wild collections) with acute
apex, longer scape and distinctly longer pedicels
(Fig. 11).
Studied specimens. Northern Laos, Houa
Phan province, Vieng Thong district, Nam Et-Phou
Louey Natural protected area, mountain ridges near
Ban Phu Vieng, 9 June 2013, J. Leong-Skornickova
et al., JLS 2452 (SING). Northern Laos, Houa
Phan province, Vieng Thong district, Nam Et-Phou
Louey Natural protected area, mountain ridges near
Ban Phu Vieng, cultivated at the Singapore Botanic
Gardens, 17 January 2014, M. Rodda, MR 542
(SING). Northern Laos, Xiangkhouang province,
Tam La, 19-X-1920, Poilane 2138 (P [P00700446,
P00700534]). Northern Laos, Xiangkhouang
province, Peak district, Oran village, 19°38´53´´N,
103°23´12´´E, primary and secondary broad-leaved
evergreen dry forest on shale sandstone slopes and
along ridge edge at 1750–1850 m, creeping epiphytic
vine 2–3 m long on tall mossy tree, common, 2 April
2015, N. T. Hiep et al., LA-VN 907 (FOF, HNL,
LE). Northern Vietnam, border area between
Phieng Luong municipality (Ha Giang province,
Turczaninowia 20 (3): 103–147 (2017)
126
Fig. 10. Hoya loyceandrewsiana T. Green: A–C (N. V. Canh, L. Averyanov, T. Maisak, AL 239, photos by L. Avery-
anov and N. V. Canh). H. lyi H. Lév. – D–F (PVT XL 010-2015, photos of V. T. Pham). H. mengtzeensis Tsiang et
P. T. Li: G, H (May 2015, Khoi s. n., photos of P. D. Q. Vuong). H. micrantha Hook. f.: I (LA-VN 2205, photos of
L. V. Averyanov).
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
127
Bac Me district) and Sinh Long municipality
(Tuyen Quang province, Na Hang district) around
point 22°38´24.3´´N, 105°20´21.3´´E, 14 November
2014, L. Averyanov et al., CPC 7431a/TM 1138/TM
1138 (LE, g. 11 – plate: digital Vietnamese ora
0254/CPC 7431a/TM 1138). Northern Vietnam,
Ha Giang province, Yen Minh district, Lao Va Chai
municipality, vicinities of Lao Va Chai village,
23º07´N, 105º08´E, 35.9 km to 27º of Ha Giang city,
primary wet evergreen broad-leaved closed forest
on limestone ridge at 1300–1400 m, lithophytic
creeping vine on open mossy rocks, white with deep
violet center, common, 9 October 1999, N. T. Hiep
et al., NTH 3470 (HN, K). Northern Vietnam, Lai
Chau province, Sin Ho district, De Phin comm.,
around point 22°19′05.9′′N, 103°13′53.8′′E,
degraded primary and secondary evergreen broad-
leaved forest on shaly limestone at 1600 m, semi-
woody creeping vine 2–4 m long, owers, white,
corona purple, 5 October 2016, L. Averyanov et al.,
CPC 8243 (LE – photo). Northern Vietnam, Lao
Cai province, Bat Xat district, Yty village, 2000 m,
14 October 2014, N. L. Orlov s. n. (LE – photos).
Northern Vietnam, Nghe An province, Ky Son
district, Na Ngoi municipality, eastern slopes of
Phu Xai Lai Leng Mountains, primary broad-leaved
and mixed forest (with Cunninghamia konishii) on
very steep mountain slopes on granite at 1900 m,
19°13´37.5´´N, 104°06´11.8´´E, creeping epiphytic
vine on mossy tree, owers white, corona pinkish-
purple, common, 20 October 2013, L. Averyanov
et al., CPC 6030 (LE). Northern Vietnam, Son La
province, Moc Chau district, Van Ho municipality,
Hua Tat village, 20º46´18´´N, 104º47´29´´E,
broad-leaved evergreen forest with Pinus wangii
and Podocarpus pilgeri on limestone at 1200–1350
m, creeping herbaceous wine to 3 m long, owers
white to light pink with red center, not rare, 28
October 2006, N. T. Hiep, L. Averyanov, P. V. The,
HAL 9310 (HN, LE). Northern Vietnam, Thanh
Hoa province, Thuong Xuan district, Bat Mot
municipality, Vin village, Xuan Lien nature reserve,
primary broad-leaved evergreen wet forest on shale
at 1000–1200 m, 19°58´18.2´´N, 104°59´24.0´´E,
creeping epiphytic vine on tall trees, owers white,
corona purple-violet, not common, 2 November
2013, L. Averyanov, N. T. Hiep, N. S. Khang,
CPC 6598 (LE). Northern Vietnam, Thanh Hoa
province, Thuong Xuan district, Bat Mot commune,
Vin village, Xuan Lien nature reserve, primary
evergreen broad-leaved forest, mixed with conifer
species such as Fokienia hodginsii, Cunninghamia
konishii, Dacrycarpus imbricatus, 19°57´N,
105°04´E, 1000 m, epiphyte creeping vine with
white latex to 2 m long, in shade, umbels of 4–5
owers, white, purple in center, not common, 3
November 2015, P. V. The, N. M. Toan, D. T. Anh,
PVT XL 010-2015 (HN). Southern Vietnam, Lam
Dong province, Lac Duong district, evergreen
mountain forest, 10 October 2016, N. X. Son,
L. Averyanov, T. Maisak, AL 234 (LE, LE – photos).
Hoya mengtzeensis Tsiang et P. T. Li,
1974, Acta Phytotax. Sin. 12, 1: 120.
Fig. 10G, H.
Described (Tsiang, Li, 1974) from southern
China (“China, Yunnan, Mengtze, Taitang”). Type
(“23 May ?, A. Henry 11368”) – NY [NY00318643]
(holotype), A [A00076419], E [E00275184], K
[K000873050], MO [MO-2107366] (isotypes).
Vernacular name in Vietnam. Cẩm cù vân nam.
Habitat, phenology and conservation status.
Epiphytic vine. Primary and secondary evergreen
humid broad-leaved and coniferous forests on
granite. Fl. April – June. Very rare. Estimated IUCN
Red List status – DD.
Distribution. Vietnam (Lam Dong province).
SW. China (Yunnan).
Notes. This is the rst record of this rare species
in Vietnam. The discovered locality in southern
Vietnam is more than 1500 km (to the east south east)
away from the main area of the species distribution
in south-western Yunnan.
Studied specimens. Southern Vietnam, Lam
Dong province, Bidoup – Nui Ba national park, May
2015, Khoi s. n. (LE – photo).
Hoya micrantha Hook. f.,
1883, Fl. Brit. India 4: 55; Rodda, Simonsson
Juhonewe, 2013, Webbia 68, 1: 12.
Described from the southern part of peninsular
Myanmar (“Tenasserim: Mergui”). Lectotype
(“Myanmar, Tenasserim, Mergui, Grifth, W.,
3798”) – K [K000278011], lectotype designated by
Rodda and Simonsson Juhonewe (2013).
= H. pseudovalifolia Costantin, 1912, Fl. Indo-
Chine 4: 139.
– H. oblongacutifolia auct. non Costantin: Pham
H.H., 2003, Ill. Fl. Vietnam 2: 750, g. 7001.
Fig. 10I, 12A, B.
Vernacular name in Vietnam. Cẩm cù hoa nhỏ.
Habitat, phenology and conservation status.
Creeping epiphytic and lithophytic vine to 10 m
long. Primary and secondary dry broad-leaved
evergreen lowland forests on any kind of mother
rocks, commonly in open habitats, 20–500 m.
Fl. March – May, October. Locally very common.
Estimated IUCN Red List status – DD.
Turczaninowia 20 (3): 103–147 (2017)
128
Fig. 11. Hoya lyi H. Lév. Digital Vietnamese ora 0254/CPC 7431a/TM 1138. Photos, correction and design by
L. Averyanov and T. Maisak.
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
129
Fig. 12. Hoya micrantha Hook. f.: A, B (LA-VN 2205, photos of L. V. Averyanov). H. multiora Blume: C–E (CPC
2433, photos of L. Averyanov). H. nummularioides H. Lév.: F–H (PVT DL 014-2015, photos of N. V. Canh). H. ob-
longacutifolia Costantin: I (2014, N. V. Canh, AL 241, photos of N. V. Canh).
Turczaninowia 20 (3): 103–147 (2017)
130
Distribution. Cambodia (Kampot and Sihanouk-
ville provinces), Laos (Champasak, Bolikhamsai
and Vientiane provinces), Vietnam (Ba Ria – Vung
Tau, Dak Lak and Lam Dong provinces). Thailand,
S Myanmar.
Notes. Presented data represent signicant ad-
ditional records of this rare species known earlier
by few collections in southern Cambodia, Laos and
Vietnam (Rodda et al., 2013).
Studied specimens. Southern Cambodia, to
the N of Sihanoukville town, Kaoh Rong Samloem
Khong Island in Siam Gulf, low hills, 10°36´45´´N,
103°18´38´´E, dry evergreen lowland forest, 19
November 2011, T. Maisak et al., 843a (LE – photo).
Central Laos, Vientiane province, Vang Vieng
district, Nathong village, about 5 km to the W of
Vang Vieng town, Tham Kang Mt., 18°55´51.4´´N,
102°23´50.6´´E, dry broad-leaved primary and
secondary evergreen forest on limestone mountains
composed by solid crystalline limestone at 300–500
m, semi-woody epiphytic vine to 10 m long, owers
white, fragrant, corona purple, not common, 14
March 2013, N. T. Hiep, L. Averyanov, N. S. Khang
et al., LA-VN 374 (FOF, HNL, LE, LE – photo).
Central Laos, Bolikhamsai province, Thaphabat
district, Nam Bon village, Phou Khao Khouay
national park, Tad Xai Waterfall, 18°27´25.9´´N,
103°08´17.5´´E, degraded primary and secondary
evergreen dry forest along river on eroded sandstone
at 340 m, creeping semi-woody epiphytic vine
2–4 m long in rather open stream shrubs, owers
yellowish-pink, corona reddish-brown between
lobes, very common, 11 April 2017, L. Averyanov et
al., LA-VN 2205 (LE). Southern Laos, Champasak
province, Xe Pian National protected area,
secondary vegetation along stream with occasional
Tectona, 25 October 2015, M. Rodda et al., MR1490
(SING). Southern Vietnam, Dak Lak province,
Chu Yang Sin Mountains, 2014, N. V. Canh s. n.
(LE – photos). Southern Vietnam, Dalat, 1960,
Tixier 50 (P [P05391678]). Southern Vietnam, in
montibus Dinh ad Baria in S. Cochinchine, 1866,
Pierre 4329 (P [P00476431]).
Hoya multiora Blume,
1823, Cat. Plant. Buitenzorg: 49; id., 1826. Bij-
dragen 16: 1064; Costantin, 1912, Fl. Indo-Chine 4:
128; Li et al., 1995, Fl. China 16: 230; Pham H.H.,
2003, Ill. Fl. Vietnam 2: 749, g. 6998; Tran T.B.,
2005, Checklist Pl. Sp. Vietnam 3: 67; Newman et
al., 2007, Checklist Vasc. Pl. Lao PDR: 70; The,
Averyanov, 2012, Taiwania 57: 51, 53, g. 3C, D.
Fig. 12C–E.
Described from Java (“Crescit: in fruticetis mon-
tanis Javae occidentalis”). Lectotype (“Indonesia,
Java [prope umine Tjapaes? Kietpil?, Salleh], 16
Sep 1820, s. coll., s. num.”) – L [L0004333] desig-
nated by Rodda et al. (2017).
Vernacular name in Vietnam. Cẩm cù tên lửa.
Habitat, phenology and conservation status.
Humus epiphytic undershrub. Primary broad-leaved
evergreen forests on any kind of mother rocks, com-
monly on old tall trees, (500)600–1200 m. Fl. March –
July. Rare. Estimated IUCN Red List status – DD.
Distribution. Cambodia (Koh Kong province),
Laos (Bolikhamxai, Houphan, Khammouan and
Phongsali provinces), Vietnam (Hoa Binh, Gia Lai,
Hai Phong area, Hanoi area, Kon Tum, Ninh Thuan
and Quang Ninh provinces, “Cochinchina”). Myan-
mar, S. China (Guangxi, Yunnan), Thailand, Malay-
sia, Indonesia, Philippines.
Notes. Widespread and extremely variable spe-
cies not too common in eastern Indochina. Here we
report many more veried records of this species
that were known before.
Studied specimens. Cambodia, Koh Kong pro-
vince, Region de Kamchay et montagne de l´Elephant,
1917-12, A. J. B. Chevalier 36428 (P [P00700445]).
Cambodia, Koh Kong province, Region de Kam-
chay, Mont de l´Eléphant, 1919-8-11, E. Poilane 317
(P[P00700444]). Central Laos, Bolikhamxai prov-
ince, Nape et Ban ho, December 1903, C. J. Spire
1484 (P [P05207687, P00700442, P00700488]).
Central Laos, Khammouan province, Phon Thane,
December 1903, C. J. Spire 1569 (P [P00700489,
P00700490, P00700491]. Central Laos, Kham-
mouan province, Nakai Nam Theun, 17°36´52´´N,
105°43´15´´E, 835 m, liana, 2006-5-22, M. F.
Newman et al., 1216 (P [P05029369]). Central
Laos, Khammouan province, Nakai Nam Theun,
17°38´33´´N, 105°44´9.996´´E, 1002 m, 2006-5-22,
M. F. Newman et al., 1422 (P [P00700439]. North-
ern Laos, Houphan province, Hem district, Na-
coc village, Puphadeng mountain, 20°09´52.6´´N,
103°10´19.4´´E, primary and secondary broad-
leaved evergreen open dry forest on karstic lime-
stone at 1000–1200 m, epiphytic undershrub on
old trees on mountain top, not common, 12 April
2015, N. T. Hiep et al., LA-VN 1438 (FOF, HNL,
LE). Northern Laos, Phongsali province, Muong
May district, 21°12´32´´N, 102°53´44´´E, highly
degraded dry evergreen broad-leaved forest along
tops of hill ridge composed with shale at 1250–1400
m, epiphytic undershrub with erect stems to 1 m
tall on old mossy tree, owers white to light yel-
lowish, not common, 22 April 2011, L. Averyanov,
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
131
P. V. The, CPC 2433 (LE – photos). Northern Vi-
etnam, Hai Phong City area, secondary evergreen
broad-leaved lowland forest, 2014, N. V. Canh s. n.
(LE – photos). Northern Vietnam, Hanoi area, Mont
Bavi, 1888-6-9, B. Balansa 2086 (P [P00700484,
P00700485, P00700486]). Northern Vietnam, Ha-
noi area, Mont Bavi, epiphyte, 1888-7-24, B. Ba-
lansa 2087 (P [P00700487]). Northern Vietnam,
Hanoi area, Mont Bavi, epiphyte, 1940-6-4, P. A.
Petelot 7197 (P [P00700492]). Northern Vietnam,
Hoa Binh province, Lac Son district, Ngoc Son mu-
nicipality, Khu village, 20°27´42´´N, 105°18´34´´E,
611 m, primary closed evergreen broad-leaved low-
land forests on foothill of limestone mountains, oc-
casional, epiphyte, 28 July 2006, P. K. Loc, N. S.
Khang, N. T. Vinh, HAL 9037 (LE). Northern Vi-
etnam, Quang Ninh province, Taai Wong Mo Shan
and vicinity, Chuk-phai, Ha-coi, 1936-11, W. T.
Tsang 27201 (P [P00700441]). Southern Vietnam,
Dak Lak province, Chu Yang Sin Mountains, prima-
ry and secondary evergreen broad-leaved mountain
forest, 2014, N. V. Canh, cultivated in private gar-
den in Buon Ma Thuot City, photos of N. V. Canh,
AL 247 (LE –photos). Southern Vietnam, Gia Lai
province [prov. Qui Nhon], An Khe, 400–500 m, epi-
phyte with milky latex, 1930-8-9, E. Poilane 17956
(P [P00700443, P00700444]). Southern Vietnam,
Kon Tum province, Ngoc Linh Mountains, primary
and secondary evergreen broad-leaved mountain
forest, 2015, N. V. Canh s. n. (LE – photos). Sou-
thern Vietnam, Ninh Thuan province, Ninh Hai dis-
trict, Vinh Hai municipality, E slopes on Nui Chua
mountains, 11°43´52´´N, 109°08´35´´ E at 800–950
m, primary evergreen closed dry forest on rocky
mountain slopes composed with granite, epiphyte,
not common, 31 March 2004, J. Regalado et al., HLF
4456 (LE – photo). Southern Vietnam, Ninh Thu-
an province, Phanrang, Cana, 700–800 m, epiphyte
with milky latex, 1925-10-16, E. Poilane 12316 (P
[P00700494]), 1925-10-28, E. Poilane 12516 (P
[P00700495]). Southern Vietnam, Ninh Thuan
province, Phanrang, Ca-na, 300 m, 1923-11-9, E.
Poilane 8505 (P [P00700493]). Southern Vietnam,
Cochinchina ad ontem Knewanh, 1870-9, L. Pierre
s. n. (P [P00700502]).
Hoya nummularioides Costantin,
1912, Fl. Indo-Chine 4: 129; Pham H.H., 2003,
Ill. Fl. Vietnam 2: 750, g. 7000.
Fig. 12F–H.
Described from S. Cambodia and Laos (“Cam-
bodge: Kompong-track (Geoffray). – Laos: Bassac,
Kong (Thorel)”). Lectotype (“Kampong Trach,
Kampot province, Cambodia, C. Geoffray 485,
1905-10-3, …”) – P [P00639776], isolectotype – P
[P00639777]; lectotype here designated.
Vernacular name in Vietnam. Cẩm cù num.
Habitat, phenology and conservation status.
Epiphytic creeping vine to 2 m long with white la-
tex. Dry dipterocarp forests and woodlands, on thin
ferralitic grey to brown rocky soils, 200 m. Fl. Octo-
ber – November. Locally common. Estimated IUCN
Red List status – DD.
Distribution. Cambodia (Kampot province),
Laos (Savannakhet, Bassac and Sainyabuli provinc-
es), Vietnam (Dak Lak province). Thailand.
Notes. The lectotype chosen by D. H. Kent in No-
vember 1988 (in sched.) had been never published.
It is conrmed and validated here. This species is
here newly reported for the ora of Vietnam.
Studied specimens. Cambodia – Laos, Ex-
pédition du Me-Kong, Paklai, Kouy, Bassac,
Laos, C. Thorel 2318, 1866/1868 (P [P00639778,
P00639779, P00639780, P00639781, P00639782,
P00639783]). Southern Vietnam, Dak Lak prov-
ince, Buon Don district, Krong Na municipality,
Yok Don national park, 13°04′N, 107°37′E, dry di-
pterocarp forest and woodland, on thin ferralitic grey
to brown rocky soils at 200 m, epiphytic creeping
vine with white latex grow in humus pocket trees,
to 2 m long on Dipterocarpus spp., locally common,
herbarium specimen prepared from cultivated plant
collected from the wild, 18 November 2015, N. V.
Canh PVT DL 014-2015 (LE, HN).
Hoya nutans Aver. et V. T. Pham, sp. nov.
Fig. 13.
Type (“16 July 2016, L. Averyanov, T. Maisak,
CPC 1592e /11531”) – LE (holotype, isotypes),
herbarium specimen prepared from cultivated plant
collected in N. Vietnam (“N. Vietnam, Hoa Binh
province, Lac Son district, Tu Do municipality, Mon
village, around point 20°25′29′′N, 105°19′36′′E,
primary broad-leaved forest on steep rocky slopes
of remnant mountain composed with solid crystal-
line highly eroded limestone at elevation 500–700
m a. s. l., semi-woody vine, occasional, 25 March
2011, N. Q. Hieu, L. Averyanov, N. T. Hiep, P. K.
Loc, P. V. The, N. T. Vinh, T. B. Ngan, N. Tap, D.
D. Dao, V. T. Ha, T. Maisak, L. Osinovetz, CPC
1592e”). Plate: digital Vietnamese ora 0258/CPC
1592e/11531, g. 13.
Etymology. Species name refers nutant owers,
placed on long slender weak pedicel.
Vernacular name in Vietnam. Cẩm cù bon giả.
Description. Epiphytic vine with clear sap to
5 m long. Stem dull pale olive-green, later dull
Turczaninowia 20 (3): 103–147 (2017)
132
brownish-grey or light grey, relatively thin, rather
straight, terete, (1.2)1.5–2(2.5) mm in diam.,
sparsely shortly hairy when young, glabrous when
mature, with sparse adventitious roots and leafy
throughout; internodes (8)10–18(20) cm long.
Leaves petiolate; petiole usually curved or slightly
twisted, (0.6)1–2.8(3.2) cm long, (2.5)3–3.5(4) mm
in diam., almost terete, dull green to olive-green,
sometime with dirty purple tinge, shortly sparsely
hairy; leaf blade not much eshy, coriaceous, ovate,
(8)9–15(16) cm long, (4.5)5–9(11) cm wide, almost
at to slightly curved, cordate, round, or sometime
cuneate at the base, shortly acuminate, uniform
green above, with distinct dark green arching
nerves, light green to whitish below, abaxial surface
with stiff sparse hairs when young (can be seen by
naked eye) broadening and blackish at the base,
adaxially glabrous, old leaves entirely glabrous,
with distinct midvein and 4–6 pairs of irregularly
arching lateral veins adaxially, arising at 40○–60○,
abaxial surface with prominent midrib, and hardly
visible lateral veins. Inorescence an extra-axillary
umbel, arising often from old leaess apical part of
stem, with (14)16–20(25) owers; peduncle notably
short, stout, cylindrical, (0.3)0.5–2.5(3) cm long,
(1)1.2–1.6(2) mm in diam., green, dull olive-green
or green-grey, sparsely shortly hairy to subglabrous,
rachis capitate to shortly cylindrical, (4.5)5–8(10)
mm long, 2.5–3 mm in diam., with several irregular
whorls of small persistent triangular oral bracts;
pedicels white to light reddish-pink, lightening to
the apex, cylindrical, slender, weak, nutant, (2.8)3–
3.4(3.6) cm long, (0.7)0.8–1(1.1) mm in diam.,
glabrous. Flowers with weak sweet fragrance,
widely opening, (1.5)1.6–1.7(1.8) cm in diam.
Calyx light reddish-brown, almost at, glabrous,
of 5 sepals almost free at the base, sepals, narrowly
triangular, obtuse to subacute, (2)2.1–2.2(2.3) mm
long, (0.9)1(1.1) mm wide near base, sparsely
hairy outside, glabrous inside. Corolla pentagonal,
shallowly campanulate, eshy, pure white above,
white with light pink tint below, (1.5)1.6–1.7(1.8)
cm in diam.; densely hirsute adaxially, glabrous and
smooth abaxially, tube 6–7 mm long, lobes 4.4–5.5
mm long, 7–9 mm broad, with slightly recurved
margins, and recurved tip. Corona glossy, yellowish-
white, of 5 lobes, (2)2.2–2.4(2.6) mm tall, (8.2)8.5–
8.8(9) mm in diam., grooved between lobes; lobes
ovoid pyramidal in outline, slightly concave above,
(4.5)4.6–4.8(5) mm long including adnate part,
free part 1.9–2 mm, and (1.9)2–2.2(2.4) mm wide,
at the base rhomboid elliptic, with basal revolute
margins; outer process (when fresh) broadly conoid,
obtuse, slightly erect, pale yellow; inner process
conoid, acute, slightly erect, (0.7)0.8–0.9(1) mm
long, straight, almost meeting above gynostegium.
Style head discoid oblate, (0.8)0.9–1.1(1.2) mm
tall, (2.3)2.4–2.5(2.6) in diam.; anther appendages
white, scarious. Pollinarium: corpusculum narrowly
rhomboid, angled, 0.2–0.25 mm long, 0.1–0.15
mm wide; translators very short, about 0.05 mm
long; pollinia oblong, (0.6)0.6–0.7(0.8) mm long,
0.1–0.15 mm wide, bright yellow; germinating crest
rather indistinct, light yellowish-hyaline, extending
from translator to pollinium apex. Carpels 2, free,
half bottle-shaped, densely connivent each other,
1.8–2 mm tall, 0.8–0.9 mm wide at the base,
articulated apically to white, oblate stigma head,
(0.6)0.7–0.8(0.9) mm tall, (1.8)2–2.2(2.3) mm in
diam.
Habitat, phenology and conservation
status. Primary broad-leaved forests on rocky
karstic limestone, commonly on steep slopes near
mountaintops, 500–700 m. Fl. July. Occasional.
Estimated IUCN Red List status – DD.
Distribution. Vietnam (Hoa Binh province). En-
demic.
Notes. This species most closely resembles
H. bonii, H. carnosa and H. fungii, but can be distin-
guished by the presence of stiff sparse hairs clearly
visible by naked eye and blackish color at the abax-
ial base of the lamina (the three other species have
either glabrous leaves or ne pubescence visible un-
der magnication only), campanulate owers with
pentagonal corolla (rotate corolla in the three other
species) and corona lobes yellowish-white, ovoid-
pyramidal with outer process obtuse (vs. pinkish,
acute or acuminate corona lobes in the three other
species).
Hoya oblongacutifolia Costantin,
1912, Fl. Indo-Chine 4: 139; Tran T.B., 2005,
Checklist Pl. Sp. Vietnam 3: 67.
Fig. 12I, 14A–C.
Described from southern Vietnam (“Mt. Deon-
ba, Tay-ninh, Pierre”). Lectotype (“Austro-Cochin-
china, in montibus Deon Ba ad Tay Ninh”, Apr 1866,
Pierre 4528”) – P [P00639820], isolectotypes – P
[P00639821, P04025652, P00639822, P05207933];
lectotype here designated.
= Hoya graveolens Kerr, 1939, Bull. Misc. In-
form. Kew. 8: 461; Rodda et al., 2012, New Hoya
Vietnam: 4, syn. nov.
Described from central Thailand. Lecto-
type (“Thailand, Sriracha, 15 May 1920, Kerr
4245”) – BM [BM001014260], isolectotypes – K
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
133
Fig. 13. Hoya nutans V. T. Pham et Aver. Digital Vietnamese ora 0258/CPC 1592e. Photos, correction and design by
L. Averyanov and T. Maisak.
Turczaninowia 20 (3): 103–147 (2017)
134
Fig. 14. Hoya oblongacutifolia Costantin: A–C (2014, N. V. Canh, AL 241, photos of N. V. Canh). H. pachyclada
Kerr: D–F (HLF 7241, photos of L. Averyanov). H. pandurata Tsiang: G–I (N. V. Canh s. n., 2016, AL 236, photos
of N. V. Canh).
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
135
[K000215162], P [P00700505]; designated by Rod-
da et al. (2012, p. 4).
Habitat, phenology and conservation status.
Lithophytic and epiphytic semi-woody vine to 8
m long. Primary and secondary evergreen, broad-
leaved lowland forests on any kind of soils, often
on low karstic limestone hills, 50–300 m. Fl. April,
January – February. Not common. Estimated IUCN
Red List status – DD.
Distribution. Vietnam (Dak Lak and Kien Giang
provinces). Thailand.
Notes. Original material of H. oblongacutifolia
was only indicated as “Mt. Deon-ba, Tay-ninh,
Pierre”. Five duplicates have been found at P.
The one with barcode [P00639820] is fertile and
well preserved and is therefore here designated as
lectotype. H. graveolens Kerr (1939) was reported
as a new record from Vietnam in 2013 (Rodda et al.,
2013) and only subsequent examination of original
material of H. oblongacutifolia allowed to clarify
that the two names should be applied to the same
taxon.
Studied specimens. Southern Vietnam,
Dak Lak province, Ea H’leo district, primary
and secondary evergreen, broad-leaved lowland
forest on alluvial soils, 2014, N. V. Canh, AL 241
(LE – photos). Southern Vietnam, Kien Giang
province, Kien Luong district, Binh An commune,
50 m, 10°08’23”N, 104°38’27”E, 9 April 2009,
Ly, 521 (HN, P, SING, VNM). Southern Vietnam,
Kien Giang province, Hang Tien Karst Hill, 45
m, 10°11’04”N, 104°35’41”E, 4 May 2007, Ly et
al., 61 (VNM); Mo So (Bai Voi) Karst Hill, 47 m,
10°13’21”N, 104°36’54”E, 16 April 2008, Ly et al.,
125 (VNM); Ba Tai Karst Hill, 99 m, 10°10’17”N,
104°36’07”E, 12 April 2008, Ly et al., 185 (VNM).
Hoya pachyclada Kerr,
1939, Bull. Misc. Inform. Kew. 8: 462.
Fig. 14D–F.
Described from Thailand (“Siam, Kawnken,
Pu Wieng, circiter 300 m., on trees in deciduous
Pentacme-Shorea forest, Kerr 20007”). Lectotype
(“Siam, Kaun Ken, Pu Wieng, 300 m, 1931-2-6,
A.F.G. Kerr 20007”) – BM [BM001014253],
isolectotypes – BK [BK257734], K [K000545616],
P [P00700508]; lectotype here designated.
Vernacular name in Vietnam. Cẩm cù khô.
Habitat, phenology and conservation status.
Humus epiphytic or occasionally lithophytic
undershrub or semi-woody vine to 4 m long. Primary
and secondary broad-leaved open evergreen and
deciduous dry lowland forests and woodlands on any
kind of mother rocks, often on thin, ferralitic soils,
20–220 m. Fl. March – April. Locally common.
Estimated IUCN Red List status – DD.
Distribution. Cambodia (Koh Kong and Pur-
sat provinces), Laos, Vietnam (Dak Lak and Thua
Thien – Hue provinces). Thailand.
Notes. This is the rst record of the species for
Vietnam. It was observed in visited localities as a
quite common plant in dry lowland primary and
secondary forests. It is also not rare in Cambodia
and Laos. The color of the corolla is variable from
almost white to purple even within one population
(based on observation in Thailand and Vietnam).
Studied specimens. Cambodia, eastern part of
Cardamom Mountains, foothills of Phnom Aural
Mountain at 19 m, 11°54′457′′N, 104°07′257′′E, 25
November 2012, T. Maisak et al., 945 (LE). Cam-
bodia, Kake, 2-1976, Harmand 449 (P [P05207917,
P05207918, P05207916]). Cambodia, Dangrek,
Ta Trau, Stung Treng, epiphyte, 13-3-1928 M. Poi-
lane 14906 (P [P04551121]). Cambodia, Pursat,
Ko Virk, Kang Chon, 9-5-1928, Poilane s. n. (P
[P05207915]). Southern Vietnam, Dak Lak prov-
ince, Buon Don district, Krong Na municipality, Yok
Don national Park, Yok Don Ridge, 12º51´36´´N,
107º42´22´´E, dry open semi-deciduous diptero-
carp forest with bamboo on thin ferralitic soil at
180–220 m, creeping epiphytic vine 0.5–1 m long,
owers white to light yellowish, common, 20 March
2008, N. T. Hiep et al., HLF 7241 (HN, LE, MO).
Southern Vietnam, Dak Lak province, Buon Don
district, Krong Na municipality, Yok Don national
park, 13°04′13′′N, 107°37′57′′E, dry dipterocarp
forest and woodland, on thin ferralitic grey to brown
rocky soils at about 200 m, epiphytic vine 1–3 m
long, owers white to yellowish, very common,
27 March 2008, N. T. Hiep et al., HLF 7394 (HN,
MO). Southern Vietnam, Thua Thien – Hue prov-
ince, Nam Dong district, Thuong Lo municipality,
along Cha Mang stream, 16°07′46′′N, 107°44′24′′E,
remnants of primary evergreen broad-leaved low-
land forest on very steep hill slopes and rocky river
valley composed with stratied shale and sandstone
at 50–70 m, creeping epiphytic and lithophytic vine
2–4 m long on tall trees, owers white, center red-
dish, occasional, 6 April 2007, L. Averyanov et al.,
HAL 10949 (HN, LE, MO).
Hoya pandurata Tsiang,
1939, Sunyatsenia 4: 125; Tsiang, Li, 1974, Acta
Phytotax. Sin. 12, 1: 125; Li et al., 1995, Fl. China
16: 235; Kidyoo, Thaithong, 2007, Nat. Hist. Journ.
Chulalongkorn Univ. 7, 1: 47.
Fig. 14G–I.
Turczaninowia 20 (3): 103–147 (2017)
136
Described from southern China. Type (“China,
Yunnan, Sze-Mao, A. Henry 12258”) – NY
[NY00318645], isotypes – A [A00076422], E
[E00275183], K [K000873049], MO [MO2107362],
US [US00048552].
Habitat, phenology and conservation status.
Humus epiphytic undershrub with spreading,
sparsely branched shoots up to 1 m long. Primary
and secondary broad-leaved semideciduous and
evergreen dry and humid forests on any kind of
mother rocks, often on exposed mountaintops,
800–1200 m. Fl. December – January. Very rare.
Estimated IUCN Red List status – DD.
Distribution. Laos (Phongsali province),
Vietnam (Bac Kan province). S China (Yunnan),
Thailand.
Notes. The location cited below presents new
records for the ora of Laos and Vietnam.
Studied specimens. Northern Laos, Phongsali
province, Boun Neua, 1200 m, semideciduous oak
forest mixed with bamboo on ridge top, cultivated
at the Singapore Botanic Gardens, vouchered as
M. Rodda MR735 on 18 September 2014 (SING).
Northern Vietnam, Bac Kan province, Cho Don
district, primary humid evergreen broad-leaved
forest, 800–900 m, 2016, N. V. Canh s. n., AL 236
(LE).
Hoya parviora Wight,
1834, Contrib. Bot. India: 37.
Fig. 15A–C.
Described from S. Myanmar (“Mawlamyine”).
Type (“Maulmyne, Myanmar, N. Wallich 33a,
1821–1829”) – E [E00179569].
Vernacular name in Vietnam. Cẩm cù lá nhỏ.
Habitat, phenology and conservation status.
Epiphytic creeping vine to 2 m long. Primary and
secondary evergreen broad-leaved forests, com-
monly in humid places along streams, 500–1000 m.
Fl. June – August. Not common. Estimated IUCN
Red List status – VU.
Distribution. Vietnam (Quang Ngai province).
Sri Lanka, Myanmar, Malaysia.
Notes. The location cited below presents a new
record for the ora of Vietnam.
Studied specimens. Central Vietnam, Quang
Ngai province without exact locality, 6 June 2016,
N. V. Canh, cultivated in private garden in Buon Ma
Thuot City, herbarium specimen prepared in 12 Oc-
tober 2016, N. V. Canh, L. Averyanov, T. Maisak,
AL 238 (LE). Central Vietnam, Quang Ngai prov-
ince, Tay Tra district, 15°07′38.2′′N, 108°17′57.5′′E,
500–1000 m, primary and secondary evergreen
broad-leaved forest, epiphytic vine to 1 m long in
humid place along stream, not common, herbarium
specimen prepared from cultivated plant collected
from the wild, 25 July 2016, N. V. Canh, PVT DL
015-2016 (HN).
Hoya polyneura Hook. f.,
1883, Fl. Brit. India 4: 54; Li et al., 1995, Fl.
China 16: 233.
Fig. 15D–G.
Described from NE India (“Sikkim Himalaya”).
Type (“Herb. Grifth, alt. 3–5000 ft., J. D. H.,
Clarke.”) – K.
Habitat, phenology and conservation status.
Humus epiphytic undershrub with spreading,
sparsely branching shoots to 1 m long. Primary and
secondary broad-leaved evergreen dry forests on
shale and sandstone mountains, commonly on tall
trees along ridge edges, 1700–1900 m. Fl. May –
June. Rare. Estimated IUCN Red List status – DD.
Distribution. Laos (Xiangkhouang province).
Bhutan, NE India, Myanmar, SW China (Xizang,
NW Yunnan).
Notes. The collection of H. polyneura in Laos
slightly extends its distribution area to the south,
as the species was already known to occur in
neighbouring Yunnan. Flowers of cultivated plants
have light sweet fragrance.
Studied specimens. North-eastern Laos, Xi-
angkhouang province, Peak district, Oran village,
around point 19°38′53′′N, 103°23′12′′E, primary
and secondary broad-leaved evergreen dry forest
on shale sandstone slopes and along ridge edge,
1750–1850 m, epiphytic undershrub with shoots to
1 m long on tall mossy tree, rare, 2 April 2015, N. T.
Hiep et al., LA-VN 906 (FOF, HNL, LE).
Hoya revolubilis Tsiang et P. T. Li,
1974, Acta Phytotax. Sin. 12, 1: 124; Li et al.,
1995, Fl. China 16: 231.
Fig. 16.
Described from southern China. Type (“Chi-
na, Yunnan, Aug 1912, G. Forrest 9108”) – A
[A00076423], isotypes – E [E00275182], IBSC
[IBSC 0005697].
Habitat, phenology and conservation status.
Epiphytic creeping vine to 6 m long. Primary and
secondary evergreen broad-leaved mountain forests.
Fl. October – November. Rare. Estimated IUCN
Red List status – DD.
Distribution. Vietnam (Lai Chau province).
Myanmar, S China (Guangxi, Yunnan).
Notes. H. revolubilis, together with other species
in the H. carnosa group, is one of the few species
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
137
Fig. 15. Hoya parviora Wight – A–C (PVT DL 015-2016, photos of N. V. Canh). H. polyneura Hook. f.: D–G (LA-
VN 906a, photos of L. Averyanov). H. vaccinioides Hook. f.: H, I (7 May 2016, N. P. Tam s. n., photos of N. P. Tam).
Turczaninowia 20 (3): 103–147 (2017)
138
Fig. 16. Hoya revolubilis Tsiang et P. T. Li. Digital Vietnamese ora 0275/AL 235. Photos, correction and design by
L. Averyanov and T. Maisak.
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
139
in the genus with uncolored latex. It is most similar
to H. salweenica Tsiang et P. T. Li (1974) found in
China, but it can be separated because of its revolute
leaf margins (when dry) and cuneate lamina base.
H. salweenica instead has at lamina margins and
round or obtuse lamina base.
Studied specimens. Northern Vietnam,
Lai Chau province, with no exact locality, 2014,
N. V. Canh, cultivated in private garden in Buon
Ma Thuot City, herbarium specimens prepared
in 12 October 2016 by N. V. Canh, L. Averyanov,
T. Maisak, AL 235, owers white, with light pleas-
ant fragrance (LE).
Hoya uniora Aver. et V. T. Pham, sp. nov.
Fig. 17.
Type (“NE. Laos, Xiangkhouang province, Peak
district, Khoang village, Pa Khao mt., around point
19°33′02.2′′N, 103°39′56.3′′E, 3 April 2015, N. T.
Hiep, L. Averyanov, N. S. Khang, N. Q. Hieu,
T. Maisak, Pheng Phengsintham, LA-VN 961”) –
LE (holotype), LE, FOF, HNL (isotypes). Plate:
digital Vietnamese ora 0255/LA-VN 961, g. 17.
Etymology. The species name refers to the
obligatory uniorous inorescence.
Description. Lithophytic and occasionally
epiphytic vine with milky latex to 35 cm long. Stem
green to grey, slender, rather herbaceous, exuose,
terete, (0.8)0.9–1(1.1) mm in diam., densely shortly
hairy, creeping by sparse adventitious roots; leafy
throughout; internodes (1.5)2–4(5) cm long. Leaves
petiolate; petiole straight (in young leaves) to
strongly curved, (3)4–8(10) mm long, (0.7)0.8–
0.9(1) mm in diam., terete, green, sparsely hairy;
leaf blade glabrous, very rigid and eshy, elliptic,
narrowly ovate to broadly ovate or almost orbicular,
(1.2)1.5–2(2.5) cm long, (0.8)0.9–1.4(1.6) cm wide,
straight or slightly curved, cuneate to roundish at
base, obtuse, round or notched at apex, with no
visible nerves; adaxial side often rough, glossy
green, with distinct longitudinal fold; abaxial side
light greenish to almost white, with glossy green or
silvery-green broad band along midrib. Inorescence
1-owered; peduncle an extra-axillary, cylindrical,
green, very short, rather stout, (3)4–4.5(5) mm long,
twice thicker than stem, densely hairy; pedicels
glabrous, glossy light green to white, cylindrical,
slender, (2.8)3–3.2(3.5) cm long, (0.8)1–1.2 mm
in diam. Flowers pendulous, sweet fragrant. Calyx
(3.2)3.4–3.6(3.8) mm in diam., at to slightly
convex, pentagonal, glabrous, of 5 sepals fused for
more than half of their length, sepals greenish to pale
light olive-brownish, broadly triangular, acute, their
free parts (0.4)0.5(0.6) mm long, (1.2)1.4(1.6) mm
wide. Corolla of 5 petals, at, eshy, pure white,
(2.6)2.8–3(3.2) cm in diam.; tube 7–8 mm long,
petals almost straight spreading, oblong triangular,
(8.5)8–9(10) mm long, 8–9 mm wide near the
base, nely densely hirsute adaxially, glabrous and
nely rough abaxially, with recurved margins; at
apex petals obtuse and unguiculate, with apiculate
recurved tip (0.7)0.8–0.9(1) mm long and wide.
Corona glossy white, of 5 segments, (3.4)3.6–3.8(4)
mm tall, (12)12.5–13.5(14) mm in diam., grooved
between lobes; lobes ovoid in outline, convex above,
(5)6–6.5(7) mm long, (3)3.2–3.4(3.6) mm wide, at
the base broadly elliptic, outer process with obtuse
outer angle, inner process attenuate into straight,
narrowly conoid acute tip (1.4)1.5–1.8(2) mm long,
as long as style head apex or slightly shorter. Style
head discoid oblate (rhomboid in sagittal section),
1.8–2 mm tall, 2.9–3.2 mm in diam.; anther caps
white, proximally yellowish; corpuscula chestnut-
purple. Pollinarium: corpusculum narrowly
rhomboid, angled, 0.6–0.7 mm long, 0.15–0.2 mm
wide; translators very short, 0.05–0.1 mm long;
pollinia oblong, (0.8)0.9–1(1.1) mm long, 0.3–0.35
mm wide, bright yellow; germination crest distinct,
yellowish-hyaline, extending from translator to
pollinium apex. Carpels 2, free, half-bottle shaped,
densely connivent each other, 1.5–1.6 mm tall,
0.7–0.8 mm in diam., articulated apically to white,
oblate stigma head apex, 1.6–1.7 mm tall, 2.8–3 mm
in diam.
Habitat, phenology and conservation
status. Creeping tiny herbaceous lithophytic and
occasionally epiphytic vine to 35 cm long. Primary
and secondary broad-leaved evergreen dry forests on
rocky karstic limestone, commonly on open mossy
rocks and cliffs near mountaintops, 1200–1450 m.
Fl. April – June. Locally common. Estimated IUCN
Red List status – DD.
Distribution. Laos (Xiangkhouang province).
Endemic.
Notes. The new species is rather unusual in the
genus because of its obligatory 1-owered inores-
cences. No other species from Indochina have this
peculiar feature that is otherwise observed in main-
land Asia only in H. mappigera Rodda et Simonsson
Juhonewe (2012b) and H. wallichii (Wight) C. M.
Burton (Burton, 1996; Rodda et al., 2016) that how-
ever have large campanulate corollas, and in a few
species from Papua.
On its plant habit and oral morphology, it may
be solely compared with H. serpens Hook. f. (Hook-
er, 1883), known from NE India. However, beside
1-owered inorescence H. uniora differs from
H. serpens in smooth (not papillose) petiolate (not
Turczaninowia 20 (3): 103–147 (2017)
140
Fig. 17. Hoya uniora Aver. et V. T. Pham. Digital Vietnamese ora 0255/LA-VN 961. Photos, correction and design
by L. Averyanov and T. Maisak.
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
141
nearly sessile) leaves, very short peduncle (much
less than 3 cm), glabrous long pedicels (longer than
2 cm, with neither hairs, no lenticular markings) and
twice larger, pure white owers (neither greenish,
yellowish or pink). The leaves almost white below
with green stripe along midrib are also very char-
acteristic, which well distinguishes the new species
even in sterile state. H. uniora allies to type section,
but exhibits certainly isolated position among mem-
bers of this section. Species of supercially similar
habit, namely – H. nummularia Hook. f. (Hooker,
1883) from NE. India and H. nummularioides Cos-
tantin (1912) known in Laos and Cambodia, as well
as H. retusa Dalzell (1852) with occasionally soli-
tary owers (occurring in India) have hardly close
relation to discovered species.
Hoya vaccinioides Hook. f.,
1883, Fl. Brit. India 4: 56; Newman et al., 2007,
Checklist Vasc. Pl. Lao PDR: 71.
Fig. 15H, I, 18A.
Described from NE India. Lectotype (“India,
Arunachal Pradesh, Mishmee mountains, by the
Thumat River. W. Grifth 3799”) – K [K000873082],
lectotype here designated.
Vernacular name in Vietnam. Cẩm cù hoa tán
nhỏ.
Habitat, phenology and conservation status.
Humus epiphyte and lithophyte with pendulous
sparsely branching shoots to 0.5 m long. Primary
broad-leaved evergreen humid forests on silicate
mountains, 1200–1500 m. Fl. April – May. Very
rare. Estimated IUCN Red List status – EN.
Distribution. Laos (Khammouan province),
Vietnam (Lam Dong province). Thailand.
Notes. Based on the habit and leaf shape this
is likely H. vaccinioides Hook. f. (Hooker, 1883),
a species that was however described based on
fruiting material only. This is the rst record of
this rare species for the ora of Vietnam. More
collections are necessary to work out if the similar
species, H. engleriana Hosseus (1907) distributed in
NE India, Nepal and N Thailand, H. dickasoniana
P. T. Li (Li, 1994) from Myanmar, and H. weebella
Kloppenb. (Kloppenburg, 2005), described based
on cultivated material without better specied
wild origin shall be considered synonyms of
H. vaccinioides. The Vietnamese collections are
characterized by ovate leaves arranged often by
three at a node and densely hirsute stem, petioles,
peduncle, pedicel and calyx. The pedicel densely
hairy with long stellate hairs pointing toward the
calyx looks unique for the genus. The species is
rare, highly endangered element of fast decreasing
primary woods and desire status of endangered
species. The collecting as ornamental plant due to
market demands is additional important factor of its
fast extinction in nature.
Studied specimens. Southern Vietnam, Lam
Dong province, Lam Ha district, primary broad-
leaved evergreen humid mountain forest, epiphyte
with pendulous shoots to 1 m long, 7 May 2016,
N. P. Tam s. n., AL 269 (LE, LE – photo). Southern
Vietnam, Lam Dong province, Bidoup Mountains,
May 2016, N. V. Canh, herbarium specimen pre-
pared from specimen cultivated in private garden in
Buon Ma Thuot City in 12 October 2016 by N. V.
Canh, L. Averyanov, T. Maisak, AL 237 (LE).
Hoya verticillata (Vahl) G. Don,
1838, Gen. Hist. 4: 128; Newman et al., 2007,
Checklist Vasc. Pl. Lao PDR: 71.
≡ Sperlingia verticillata Vahl, 1810, Skrivt. Nat.
Selsk. 6: 113.
Fig. 18B–F, 19.
Described supposedly from NE. India. Lectotype
(Flohr in Hb. Vahl ‘ex Ind. Orient. Cynanchum?’) –
C [C10006735], designated by Veldkamp et al.
(1995); possible isolectotype – C [C10006736]).
= Hoya balansae Costantin, 1912, Fl. Indo-Chine
4: 136; Pham H.H., 2003, Ill. Fl. Vietnam 2: 747, g.
6988; Tran T.B., 2005, Checklist Pl. Sp. Vietnam 3:
66, syn. nov.
Described from northern Vietnam (“Ha Long
bay, Quang Ninh province”). Lectotype (“Tonkin,
baie d’Along, B. Balansa 598, 1885–7–3”) – P
[P00645997], designated by Rodda (2017).
Habitat, phenology and conservation status.
Creeping epiphytic and lithophytic semi-woody
vine to 12 m long. Primary and secondary broad-
leaved evergreen forests on limestone, commonly
on vertical cliffs, on mossy mountain tops, and along
stream canons, 5–900 m. Fl. March – May, owers
from almost white to yellowish or pink, odourless
to very fragrant. Locally very common. Estimated
IUCN Red List status – LC.
Distribution. Cambodia (Sihanoukville
town, Kaoh Rong Samloem Khong Island), Laos
(Bolikhamsai, Louangphrabang and Vientiane
provinces), Vietnam (Hai Phong and Quang Ninh
province). NE India, Bangladesh, Thailand.
Notes. The examination of the type specimens
and of the new material of Hoya balansae reveals
a close similarity with the H. verticillata (Vahl)
G. Don (Vahl, 1810; Don, 1838) complex. Follow-
ing the study of the complex carried out in Thailand
by Kidyoo et al. (2006, 2007) the H. balansae can
be identied as belonging to group “V” based on
Turczaninowia 20 (3): 103–147 (2017)
142
Fig. 18. Hoya vaccinioides Hook. f.: A (7 May 2016, N. P. Tam s. n., photos of N. P. Tam). H. verticillata (Vahl)
G. Don: B–F (N. V. Canh s. n., 2014, AL 240).
leaf shape and base and group “VI” or “VII” based
on calyx lobe shape. Groups “V–IX” are considered
as variable forms of H. verticillata var. verticillata;
therefore, H. balansae is here considered as a new
synonym of H. verticillata.
Studied specimens. Southern Cambodia, to
the N of Sihanoukville town, Kaoh Rong Sam-
loem Khong Island in Siam Gulf, low hills around
point 10°36’45’’N, 103°18’38’’E, dry evergreen
lowland forest, 19 November 2011, T. Maisak, M.
Telepova, L. Osinovetz, 843, owered in cultiva-
tion in June 2014, owers white, with very strong
honey fragrance, corona in center purple (LE, LE –
photos). Central Laos, Vientiane province, Vang
Vieng district, Khan Mac village, 18°51’26.4’’N,
102°28’36.7’’E, secondary broad-leaved deciduous
open dry forest on limestone at 400–500 m, long
creeping semi-woody vine to 12 m long, locally
very common, 23 March 2017, L. Averyanov et al.,
LA-VN 1567 (FOF, LE). Central Laos, Bolikham-
sai province, Thaphabat district, Nam Bon village,
Phou Khao Khouay national park, Tad Xai Water-
fall, 18°27’25.9’’N, 103°08’17.5’’E, degraded pri-
mary and secondary evergreen dry forest along river
on eroded sandstone at 340 m, semi-woody epiphyt-
ic and lithophytic vine 4–6 m long in rather open
place, owers almost odorless, white, common,
11 April 2017, L. Averyanov et al., LA-VN 2194
(FOF, LE). Northern Laos, Vientiane province,
Kasi district, Si Sang Vone village, 19°06’10.9’’N,
102°10’46.1’’E, secondary and primary ever-
green dry forest on limestone at 600–750 m,
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
143
Fig. 19. Hoya verticillata (Vahl) G. Don. Digital Vietnamese ora 0280/LA-VN 1993. Photos, correction and design
by L. Averyanov.
Turczaninowia 20 (3): 103–147 (2017)
144
creeping epiphytic and lithophytic semi-woody
vine on rocky mountain top, not rare, 28 March
2017, L. Averyanov et al., LA-VN 1857 (FOF, LE).
Northern Laos, Louangphrabang province, Ngoy
district, Nong Khiew village, Ta Nang Non Moun-
tain, 20°33’29.2’’N, 102°36’54.5’’E, secondary
semideciduous and evergreen dry forest on lime-
stone at 600–650 m, semi-woody vine on mossy
rocky mountain top, common, 31 March 2017,
L. Averyanov et al., LA-VN 1928 (FOF, LE). Nor-
thern Laos, Louangphrabang province, Ngoy dis-
trict, Nong Khiew village, Ta Nang Non Mountain,
20°33’29.2’’N, 102°36’54.5’’E, secondary semi-
deciduous and evergreen dry forest on limestone
at 600–650 m, semi-woody vine on mossy rocky
mountain top, locally common, 31 March 2017,
L. Averyanov et al., LA-VN 1931 (FOF, LE). Nor-
thern Laos, Louangphrabang province, Ngoy
district, Ngoy village, Pha Noi Mountain,
20°42’53.6’’N, 102°40’34.7’’E, remnants of pri-
mary evergreen forest on limestone at 400–450 m,
epiphytic and lithophytic creeping semi-woody vine
to 6–8 m long on mossy rocky mountain top, ow-
ers white to light yellowish or pinkish, very fragrant,
very common, 1 April 2017, L. Averyanov et al.,
LA-VN 1976 (FOF, LE). Northern Laos, Louang-
phrabang province, Ngoy district, Don Khun vil-
lage, near waterfall, 20°31’36.9’’N, 102°35’15.8’’E,
remnants of primary evergreen forest on limestone
at 450–550 m, along mountain stream, semi-woody
creeping epiphyte and lithophyte vine on open rocks,
owers white, light yellowish or pinkish, fragrant,
common, 2 April 2017, L. Averyanov et al., LA-VN
1993: d-EXSICCATES OF VIETNAMESE FLO-
RA 0280/LA-VN 1993, g. 19 (FOF, LE); creeping
epiphytic and lithophytic vine 3–4 m long in open
place, owers light pinkish, very common, 2 April
2017, L. Averyanov et al., LA-VN 2015 (FOF, LE).
Northern Laos, Louangphrabang province, Pon
Xay district, between Houay Man and Nam Bo vil-
lages, Phou Hua Ben Toc Mountain, 19°57’33.1’’N,
102°25’25.8’’E, degraded primary evergreen and
semideciduous forest on limestone at 500–650 m,
long creeping semi-woody vine 6–8 m long, ow-
ers white to light yellowish, center of corona purple,
locally very common, 5 April 2017, L. Averyanov
et al., LA-VN 2115 (FOF, LE); long creeping semi-
woody vine 6–8 m long, owers white to light yel-
lowish including corona, leaves with purple tint
to dull pale dirty purple. locally common, 5 April
2017, L. Averyanov et al., LA-VN 2118 (FOF, LE).
Northern Laos, Louangphrabang province, Pon
Xay district, along the way to Bane Phou Souong
village, Pha Hiua Bin Toc Mountain, 19°57’37.0’’N,
102°25’03.0’’E, degraded primary evergreen and
semideciduous forest on limestone at 600–850 m,
creeping semi-woody epiphytic and lithophytic vine
on open rocky slope near mountain top, owers
white, corona white with purple center, not rare, 5
April 2017, L. Averyanov et al., LA-VN 2163 (FOF,
LE). Northern Vietnam, Haiphong City area, 2014,
N. V. Canh, cultivated in private garden in Buon Ma
Thuot City, L. Averyanov AL 240, photos of N. V.
Canh (LE – photos). Northern Vietnam, Quang
Ninh province, Hon Gai district, Ha Long Bay, Dau
Go Island, 20°54′N, 107°01′E, secondary broad-
leaved evergreen forest on steep limestone slopes
and vertical bluffs, at 0–100 m, lithophytic vine 3–4
m long on open rocks, owers yellowish, often with
purple tint, locally very common, 12 May 1999, N.
T. Hiep, L. Averyanov, NTH 2620 (HN). Northern
Vietnam, Quang Ninh province, Ha Long Bay, Doi
Vai Island, vine on rock, white latex, owers white,
very common in Ha Long bay, 12 April 2000, N. T.
Hiep NTH 4218 (HN). Northern Vietnam, Quang
Ninh province, Ha Long Bay, Trinh Nu Cave,
20°50′N, 107°06′E, secondary limestone forest at
elevations 0–100 m, epiphyte and lithophyte, white
owers, fragrant, common, 6 July 2003, N. X. Tam,
P. V. The, NTH 5712 (HN). Northern Vietnam,
Quang Ninh province, Ha Long Bay, Me Cung
Cave, 20○50´14´´N, 107○04´26´´E, secondary lime-
stone forest at 0–100 m, epiphyte with white latex,
owers pinkish, at base of mountain, locally com-
mon, 28 February 2003, N. X. Tam, P. V. The, NTH
5600 (HN).
Acknowledgements. Field works, results of
which are presented in this paper were nancially
supported in part by USA National Geographic So-
ciety, “Assessment of plant diversity in main lime-
stone areas of central Laos” (#9906-16) and Russian
Foundation for Basic Research “Plant taxonomy,
geography and biology in local oras of eastern
Indochina” (15-04-00419А), and were carried out
in the framework of institutional research project
of the Komarov Botanical Institute of the Russian
Academy of Sciences. We are grateful to following
persons for various support such as the organizing
of eld explorations, photography, specimen col-
lecting, eld data and kind assistance during eld-
works – Phan Ke Loc, Nguyen Tien Vinh, Nguyen
Xuan Dang, Chu Xuan Canh, Ben Rawson, Kirrily
Apthorp, Nguyen Dinh Hai, Nguyen Mau Toan, Dao
The Anh, Pham Doan Quoc Vuong, Ngo Thi Diem
My, Lam Thi Ngoc Thanh, and Vu Truong Nhat.
Averyanov L. V. et al.
Hoya in Cambodia, Laos and Vietnam
145
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