Phytotaxa 531 (2): 129–135
Copyright © 2022 Magnolia Press Article PHYTOTAXA
ISSN 1179-3155 (print edition)
ISSN 1179-3163 (online edition)
Accepted by Sin Yeng Wong: 22 Dec. 2021; published: 18 Jan. 2022
Conamomum vietnamense (Zingiberaceae), a new species from Tay Nguyen,
*, THANH-SON HOANG
, OUDOMPHONE INSISIENGMAY
, THOMAS HAEVERMANS
1 Institute of Tropical Biology, VAST, 85 Tran Quoc Toan Road, District 3, Ho Chi Minh City, Vietnam.
2 Graduate University of Science and Technology, VAST, 18 Hoang Quoc Viet, Cau Giay District, Ha Noi, Vietnam.
3 Silviculture Research Institute, Vietnamese Academy of Forest Sciences, Ha Noi 10000, Vietnam.
4 Institut de Systématique Évolution Biodiversité (ISYEB), Muséum national d’histoire naturelle, Centre national de la recherche
scientifique, École Pratique des Hautes Études, Université, des Antilles, Sorbonne Université, 45 rue Buffon, CP 50, 75005 Paris,
5 The Cabinet of the Lao Academy of Science and Technology, Ministry of Education and Sport, 100 Building, Na Haidiew Village,
Chanthabouly District, Vientiane Capital, Lao PDR.
6 Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh EH3 5LR, Scotland, UK.
Conamomum vietnamense, a new species of Zingiberaceae, is described and illustrated from Tay Nguyen (Central Highlands),
Vietnam. It is most similar to C. odorum and C. rubidum, but differs in having well-developed stilt roots, elliptic leaf blades,
narrowly ovate bracts, abaxially pubescent bracteoles, longer calyx with 2 truncate lobes, broadly obovate to orbicular
glabrous labellum, longer filament and glabrous style. Data on distribution, habitat, vernacular name, conservation status
and a colour plate of the new species, along with a key to distinguish the species of Conamomum in Cambodia and Vietnam
Keywords: Amomum, Cambodia, Conamomum, Lao PDR, new species, Vietnam
Conamomum Ridl. (1899: 121) is a small genus in the family Zingiberaceae with 11 species that grow in primary
evergreen lowland and montane forests (de Boer et al. 2018, Luu et al. 2019) in Vietnam, Cambodia, Thailand,
Peninsular Malaysia, Singapore, Sumatra and Borneo. The genus is characterized by a trilobed horned anther crest with
narrowly acute and down facing side lobes (Ridley 1899, de Boer et al. 2018). Conamomum was first established by
Ridley (1899) with one species, C. utriculosum Ridl. (1899: 122), discovered in tea gardens in Perak State, Malaysia.
Holttum (1950) later transferred this species to Amomum Roxb. (1820: 75), as Amomum utriculosum (Ridl.) Holttum
(1950: 208), and this name has been accepted by botanists for more than 50 years (Burtt & Smith 1972, Smith 1985,
1986, Sakai & Nagamasu 1998, Lamxay & Newman 2012). Recently, De Boer et al. (2018) resurrected Conamomum
at generic level based on molecular (nrITS and matK) and morphological evidence. Three species of Conamomum
have been reported in the flora of Cambodia, Lao PDR and Vietnam, C. pierreanum (Gagnep. (1906: 143)) Škorničk.
& A.D. Poulsen (2018: 20) in Kampong Chhnang, Kampong Spoe, Kampot and Kaoh Kong, Cambodia, C. rubidum
(Lamxay & N.S. Lý (2012: 166)) Škorničk. & A.D.Poulsen (2018: 20) in Khanh Hoa and Lam Dong, Vietnam, and C.
odorum Luu, H.Ð.Trần & G.Trần (2019: 56) in Khanh Hoa, Vietnam (Gagnepain 1908, Lamxay & Newman 2011, de
Boer et al. 2018, Luu et al. 2019). No records of Conamomum are known from Lao PDR.
While carrying out field work in Tay Nguyen in 2016, the first author observed several sterile plants of Zingiberaceae
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130 • Phytotaxa 531 (2) © 2022 Magnolia Press
in Loc Bac protection forests, Lam Dong Province. These were laxly caespitose plants of 3‒10 leaf shoots with rhizomes
projecting above the soil on stilt roots, elliptic laminae, smooth fruits with appressed hairs, and dried infructescences
with persistent brown bracts. These plants were initially identified as a species of Amomum. In 2017, the first author
and colleagues revisited the same collection site and the adjacent area, Nam Cat Tien protection forests in Dak Nong
Province, to collect and photograph these plants in flower, the flowers having a bright yellow labellum and trilobed
anther crest with horn-like lateral lobes curved inward. The morphological characters of the flowers show that these
plants belong to the genus Conamomum. Critical examination of the living flowers, dried specimens, and comparison
with type material and protologues of all related Conamomum in Vietnam and neighbouring countries (Ridley 1899,
1904, Holttum 1950, Gagnepain 1098, Phạm 2000, Lamxay & Newman 2011) revealed that these specimens were
different from other known Conamomum species, though the unknown taxon showed similarities to C. rubidum and C.
odorum. Significant differences in its vegetative and floral structures (see Table 1) lead us to describe and illustrate it
here as a new species to science, which we name Conamomum vietnamense.
The description and all measurements were made from mature individuals of living plants in the field, supplemented
with alcohol preserved and herbarium specimens. Type specimens of species that were morphologically similar were
examined and/or accessed as hi-resolution digital images from E, HN, P, SING, VASF and VNM (herbarium codes
follow Thiers (2018)), as well as specimen images on the website of JSTOR Global Plants (https://plants.jstor.org/).
All morphological characters were described using the terminology of Beentje (2016). A distribution map was created
using SimpleMappr (http://www.simplemappr.net/) (Shorthouse 2010). Conservation status was assessed using the
IUCN Red List Categories and Criteria version 3.1 (IUCN 2019). The extent of occurrence (EOO) and the area of
occupancy (AOO) were estimated using the web Geospatial Conservation Assessment Tool or GeoCAT (http://geocat.
kew.org/editor) (Bachman et al. 2011) with an auto-value cell width of 2 km.
Conamomum vietnamense N.S.Lý & T.S. Hoang, sp. nov. (Fig.1)
Diagnosis:—Most similar to C. odorum Luu, H.Ð.Trần & G.Trần in having yellow flowers, trilobed labellum with reflexed margins and
trilobed, yellow anther crest but differing by the presence of 20–50 cm tall stilt roots (vs. absent), elliptic to obovate-elliptic leaves
(vs. narrowly elliptic), narrowly ovate bracts (vs. ovate), abaxially pubescent bracteoles (vs. ciliate at teeth), bilobed calyx with
truncate tips (vs. tridentate with acute tips), broadly obovate to orbicular labellum (vs. obovate), filament 16–18 mm long (vs. ca. 13
mm long), and style glabrous (vs. sparsely hairy).
Also similar to C. rubidum (Lamxay & N.S.Lý) Škorničk. & A.D.Poulsen, differing by its elliptic to obovate-elliptic leaves (vs. oblong-
linear), narrowly ovate bracts (vs. obovate), abaxially pubescent bracteoles (vs. hairy at base), bilobed calyx with truncate tips (vs.
tridentate with acute tips), broadly obovate to orbicular labellum (vs. reniform), filament 16–18 mm long (vs. 7–8 mm long), and
style glabrous (vs. sparsely hairy).
Type:—VIETNAM. Lam Dong Province: Bao Lam District, Loc Bac Commune, Loc Bac protection forests, 11°46’56.47”N,
107°36’23.75”E, 705 m elev., 12 March 2017, Lý Ngọc Sâm, Lý-879 (holotype: VNM!, isotypes: E!, P!).
Description:—Laxly caespitose, clump-forming herb, 1.2–2 m tall. Rhizome horizontal, held ca. 20–50 cm above
ground by numerous stilt roots (Fig. 1B), 10–42.5 cm long, 0.5–1 cm diam., slightly aromatic; stilt roots stout, dark
brown to brown-greenish, 20–70 × 0.5–0.7 cm, glabrous; interval between pseudostems 2.8–5 cm, covered by ca. 8
distichous scales; scales hairy, broadly triangular, ca.1 × 1.5 cm, coriaceous, striate, outer surface tomentose, apex
broadly acute to acuminate with a short mucronate tip. Leafy shoots 3–10 per each clump; pseudostem 1–1.5 m tall,
with 9–16 leaves per pseudostem, swollen at base, 1.6–1.8 cm diameter, gradually becoming smaller towards apex,
green, striate, glabrous, outer surface finely reticulate; ligule 4–8 mm long, hairy, swollen at base of petiole, apex
obtuse, margin ciliate; petiole canaliculate, 5–8 mm long, green, glabrous; lamina elliptic to obovate-elliptic, striate,
27.2–39.5 × 4–6.8 cm, adaxially dark green, shiny, glabrous, abaxially lighter, glabrous except sparsely puberulous
along midvein, base attenuate, apex long caudate. Inflorescences erect, arising from branched rhizome, somewhat
congested, 1–4 per pseudostem, (8.5–)10–17.7 cm long; peduncle stout, cylindrical, (4–)4.5–10.2 × 0.6–1 cm, densely
minute pubescent, covered by about 8–14 persistent scales; peduncular scales broadly triangular at base, 0.5–0.7 ×
1.4–1.8 cm, triangular-ovate distally, 3.5–5 × 2.5–3.4 cm, brown, striate, papery, tomentose with soft hairs, apex acute
to rounded, margin ciliate; spike oblong-obovoid, (4.5–)5.5–10 × 4.5–6, bearing 25–50 bracts, 1–2 flowers open at a
time; bracts narrowly ovate, 35–51 mm long, (12–)14–22 mm at widest point, ascending and curved outward, cream
A NEW SPECIES OF CONAMOMUM VIETNAMENSE Phytotaxa 531 (2) © 2022 Magnolia Press • 131
when young, soon turning papery brown, hard, thick, striate, subtending a single flower, abaxially pubescent, apex
acuminate, persistent; bracteoles tubular, bidentate, unequal, 25–30 mm long, 10–13 mm at widest point, reddish brown,
membranous, abaxially pubescent, tube 13–18 mm long. Flowers (4.9–)5.5–5.7 cm long; calyx tubular, bilobed, 12–14
× 6–8 mm, tube 6–10 mm long, sparsely pubescent, lobes 3– 6 mm long, apex truncate; floral tube 14–16 × 4–6 mm,
white, outer surface sparsely pubescent, inner surface glabrous except for sparse glandular hair at apex; corolla lobes
glabrous, reddish, with darker red, narrow stripes; dorsal lobe elliptic, 28–33 × 17–18 mm, apex rounded and hooded;
lateral lobes oblong, 27–30 × 10–13 mm, apex short, acute; lateral staminodes triangular-linear, sometimes with a
few tiny teeth at base, 8–9 mm long, ca. 1 mm at base, pink-red 2/3 towards apex, bright yellow distally, glandular
hairs at base; labellum broadly obovate to orbicular, 35–40 × 34–37 mm, bright yellow with red stripes at margin
in basal half of labellum, glabrous, apex markedly trilobed, central lobe deeply bifid, margin undulate and reflexed.
Stamen 19–22 mm long; filament flat, distinctly incurved to labellum, 16–18 × 2.8–3 mm, yellow, glandular hairy;
anther 8–9 × 4–5 mm, yellow with glandular hairs on connective tissue, dehiscing lengthwise; anther crest trilobed,
bright yellow, central lobe 2.5–3 × 3–4 mm, triangular-ovate, apex truncate to shortly acute; lateral lobes 4.5–6 ×
1–1.5 mm, lanceolate-linear, horn-like, curved inward. Epigynous glands 1 pair, 2.4–2.6 × 1.8–2 mm, cream yellow,
glabrous. Style 39–41 × ca. 0.3 mm, white, glabrous; stigma cup-shaped, ca. 1 × 2 mm; ostiole narrowly transverse,
margin ciliate. Ovary shortly cylindrical, 2.5–3 × 3–4 mm, densely pubescent, trilocular; ovules many. Infructescence
oblong-ovoid, 5–8 × 3–5 cm, bracts persistent, light brown and papery. Mature fruit subglobose, 13–15 × 10–12 mm,
red, smooth, pubescent, calyx persistent, containing 10–15 seeds; seeds irregular subglobose, 3–3.5 ×2– 2.5 mm, aril
Phenology:—Flowering from March to May, fruiting from May to July.
Etymology:—The specific epithet “vietnamense” refers to its current discovery and distribution in Vietnam.
Distribution, habitat and conservation status:—Conamomum vietnamense is found in only three localities in Dak
Nong and Lam Dong provinces, Tay Nguyen, Vietnam (Fig. 2A). It grows on wet ground or on hill slopes throughout
the understorey of the evergreen, mixed broadleaved tropical forests which is situated within the confines of the Nam
Cat Tien protection forests in Dak R’Lap District, Dak Nong Province and Loc Bac protection forests in Bao Lam
District, Lam Dong Province. The new species grows in relatively rich, wet but well-drained soils, at altitudes of
600–700 m. We observed ten subpopulations of a total of about 700 mature clumps in the Loc Bac protection forests
and five subpopulations of a total of about 200 mature clumps found in the Nam Cat Tien protection forests. The extent
of occurrence (EOO) and the area of occupancy (AOO) were calculated to be 28.4 km2 and 16 km2, respectively (Fig.
2B). These two values meet the criteria B1 (EOO < 100 km2) for Critically Endangered and B2 (AOO < 500 km2) for
Endangered, following the IUCN Red List Categories and Criteria Version 3.1 (IUCN 2019). Although the known
habitat of the new species is part of a protected area, its forest habitat is frequently logged and disturbed, in particular
to create clearings for rubber and coffee plantations. Based on the IUCN Red List criteria (IUCN, 2019), we therefore
provisionally assess this species as Endangered (EN B2ab(iii)).
Other specimens examined (paratypes):—VIETNAM. Dak Nong Province: Kien Duc District, Dak R’lap
Commune, Nam Cat Tien protection forest, 11°50’01.50”N, 107°34’23.60”E, 602 m elev., 22 March 2017, Hoang
Thanh Son, VAFS-1356 (VAFS!). Lam Dong: Bao Lam District, Loc Bac Commune, Loc Bac protection forests,
11°47’24.71”N, 107°33’55.81”E, 638 m elev., 18 November 2016, Lý Ngọc Sâm, Lý-838 (VNM); ibid., 11°46’56.32”N,
107°36’21.65”E, 707 m elev., 28 May 2017, Oudomphone Insisiengmay and Lý Ngọc Sâm, OI 172 (VNM!, P!);
ibid., 11°47’39.63”N, 107°36’51.31”E, 710 m elev., 19 March 2017, Hoang Thanh Son, VAFS-1235 (VAFS!) and
11°46’06.9”N, 107°32’23.6”E, 620 m elev., 20 March 2017, Hoang Thanh Son, VAFS-1301 (VAFS!).
Notes:—A detailed morphological comparison between C. vietnamese and the two species most similar to it is
provided in Table 1. Conamomum vietnamense also resembles C. pierreanum by its stilt roots, persistent bracts and
the pattern of colours in the flower but the longer petioles, broadly ovate to boat-shaped bracts with cucullate apex,
bowl-shaped labellum, and globose and finely ridged fruits of C. pierreanum distinguish it from the other three species
in Cambodia and Vietnam.
With the description of C. vietnamense, the distribution of the genus in Vietnam is extended northwards to Dak
Nong Province, and one more locality in Lam Dong Province. The localities of the three Vietnamese species lie some
distance south of Lao PDR. Further field work is needed to establish whether Conamomum occurs in Lao PDR or not.
Conamomum pierreanum is relatively widespread in Thailand and Cambodia, while the three Vietnamese species are
narrow endemics, each known from one or two localities, and all under threat of habitat disturbance.
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TABLE 1. Comparison between C. vietnamense and its related species in Cambodia and Vietnam.
Characters C. vietnamense C. odorum C. rubidum C. pierreanum
Plant height 1–1.5 m to 1.2 m ca. 1.5 m 1.5–2 m
Stilt roots 20–50 cm tall above
ground absent absent 10–15 cm tall above
Ligules 4–8 mm long, hairy 1–2 mm long, glabrous 6–12 mm long, shortly
hairy ca. 10 mm long, glabrous
Petiole 5–8 mm long 2–4 mm long 5–9 mm long 20–30 mm long
Lamina elliptic to obovate-elliptic,
striate, lighter green
narrowly elliptic, striate,
lighter (sometimes light
purple) lower surface
abaxially pale green to
purplish-red lower surface
oblong, smooth, pale
green lower surface
Spike obovoid ovoid obovoid globose to ovoid
narrowly ovate 35–51 ×
(12–)14–22 mm, persistent,
ovate, 28–32 × 8–11
mm, persistent, abaxially
obovate, 36–41 × 15–35
mm, rotting at early stage,
tomentose at base
broadly ovate to boat-
shaped, 25–43× 15–20
mm, persistent, abaxially
Bracteoles abaxially pubescent abaxially ciliate hairs at
teeth abaxially hairy at base abaxially hairy
12–14 × 6–8 mm, sparsely
pubescent, bilobed, apex
17–19 × 3–6 mm,
ca. 20 × 5 mm, glabrous,
tridentate, apex acute
20–25 × 4–5 mm,
Floral tube sparsely pubescent glabrous glabrous glabrous
Corolla lobes elliptic-oblong, reddish oblong, cream oblong, reddish oblong, reddish
broadly obovate to
trilobed, 35–40 × 34–37
obovate, slightly trilobed,
ca. 26 × 16 mm, sparsely
glandular hairy at base
reniform, 30–37 × ca.
30 mm, glandular hairy
trilobed, ca. 25 × 10–15
Filament 16–18 mm long ca. 13 mm long 7–8 mm long ca.10 mm long
Style glabrous sparsely hairy near apex sparsely hairy hairy
Epigynous glands 2.4–2.6 mm long, yellow ca. 2 mm long, yellow ca. 4 mm long, white ca. 3 mm long, yellow
Ovary hairy hairy glabrous glabrous
Fruits subglobose, smooth, hairy unknown ovoid, somewhat
globose, with fine ridge,
Distribution Central Vietnam: Dak Nong
and Lam Dong Provinces
Central Vietnam: Khanh
Central Vietnam: Khanh
Hoa and Lam Dong
Cambodia and Thailand
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FIGURE 1. Conamomum vietnamense. A. Plant in natural habit; B. Basal part of mature plant showing rhizomes with stilt roots; C.
Leaves; D. Petioles and ligules (upper) with detail of ligule (lower); E. Inflorescence; F. Top view of inflorescence; G. Close-up of flower;
H. Side view of flower; I. Bracts; J. Flower; K. Bracteole; L. Calyx; M. Dorsal and lateral corolla lobes (from left); N. Floral tube and
stamen; O. Ovary and epigynous glands; P. Labellum; Q. Stamens (from left: front, side and back views); R. Mature fruit, entire and in
cross-section. Scale bars: I–N and P–R = 10 mm; O = 5 mm. Photos and plate from Lý-879.
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FIGURE 2. A. Distribution map of C. vietnamense in Vietnam; B. Extent of occurrence (EOO) and Areas of occurrence (AOO) of
Key to the species of Conamomum in Cambodia and Vietnam
1. Stilt roots absent .................................................................................................................................................................................2
- Stilt roots present ................................................................................................................................................................................3
2. Leaf blades 30–45 × 4.5–7 cm, ligules hairy, bracts rotting at early stage, calyx glabrous, corolla lobes reddish, labellum reniform,
ovary glabrous (Vietnam) .................................................................................................................................................. C. rubidum
- Leaf blades 25–30 × 3– 3.5 cm, ligules glabrous, bracts persistent, calyx pubescent, corolla lobes cream, labellum obovate, ovary
hairy (Vietnam) ....................................................................................................................................................................C. odorum
3. Stilt roots ≥ 20 cm long, petiole 5–8 mm long, calyx bilobed, 12–14 mm long, and sparsely pubescent, labellum obovate-orbicular,
A NEW SPECIES OF CONAMOMUM VIETNAMENSE Phytotaxa 531 (2) © 2022 Magnolia Press • 135
ovary hairy, fruit smooth and hairy (Vietnam) ............................................................................................................ C. vietnamense
- Stilt roots < 20 cm long, petioles 20–30 mm long, calyx tridentate, 20–25 mm long and glabrous, labellum bowl-shaped, ovary
glabrous, fruit finely ridged and glabrous (Cambodia, Thailand) ................................................................................ C. pierreanum
The research of the first and fourth authors was funded by the International collaboration project between Vietnam
Academy of Science and Technology, Vietnam and Centre national de la recherche scientifique, France 183 (VAST.
HTQT.PHAP.02/N16-17). We thank the Franklinia Foundation who contributed to this fieldwork through a grant to
the Muséum national d’histoire naturelle for the Flora of Cambodia, Laos and Vietnam project. This paper is part of
a project (AAP3-96) supported by the Sud Expert Plantes Développement Durable programme. The Royal Botanic
Garden Edinburgh (RBGE) is supported by the Scottish Government’s Rural and Environmental Science and Analytical
Bachman, S., Moat, J., Hill, A.W., de Torre, J. & Scott, B. (2011) Supporting Red List threat assessments with GeoCAT: geospatial
conservation assessment tool. ZooKeys 150: 117–126.
Burtt, B.L. & Smith, R.M. (1972) Key species in the taxonomic history of Zingiberaceae. Notes from the Royal Botanic Garden, Edinburgh
de Boer, H., Newman, M., Poulsen, A.D., Droop, A.J., Fér, T., Lê, T.T.H., Hlavatá, K. Lamxay, V., Richardson, J.E., Steffen, K. &
Leong-Škorničková, J. (2018) Convergent morphology in Alpinieae (Zingiberaceae): Recircumscribing Amomum as a monophyletic
genus. Taxon 67 (1): 6–36.
Gagnepain, F. (1906) Zingibéracées nouvelles de l’herbier du muséum. 15e note. Bulletin de la Société botanique de France 53: 132–150.
Gagnepain, F. (1908) Amomum. In: Lecomte, P.H., Fl. Indo-chine 6 (1), xxx, pp. 102–117.
Holttum, R.E. (1950) The Zingiberaceae of the Malay Peninsula. Gardens’ Bulletin Singapore 13: 224–236
IUCN Standards and Petitions Committee (2019) Guidelines for Using the IUCN Red List Categories and Criteria. Version 14. Prepared
by the Standards and Petitions Committee. Available from: https://www.iucnredlist.org/resources/redlistguidelines.pdf (accessed 7
Lamxay, V. & Newman, M.F. (2012) A revision of Amomum (Zingiberaceae) in Cambodia, Laos and Vietnam. Edinburgh Journal of
Botany 69: 99–206.
Luu, H.T., Tran, H.D., Nguyen, Q.D., Nguyen, T.Q.T. & Tran, G. (2019) Conamomum odorum, a new species of Zingiberaceae from
Central Vietnam. Academia Journal of Biology 41 (3): 55–59.
Phạm, H.H. (2000) Amomum. In: Cay Co Vietnam: An illustrated flora of Vietnam 3. Ho Chi Minh City, Nha Xuat Ban Tre. pp. 434–
Ridley, H.N. (1899) The Scitamineae of the Malay Peninsula. Journal of the Straits Branch of the Royal Asiatic Society 32: 85–184.
Ridley, H.N. (1909) The Scitamineae of the Philippine islands. Philippine Journal of Science. Section C, Botany 4: 155–199.
Schumann, K.M. (1904) Zingiberaceae. In: Engler, A. (Ed.) Das Pflanzenreich, IV, 46 (Heft 20). Leipzig. pp. 1–458.
Sakai, S. & Nagamasu, H. (1998) Systematic Studies of Bornean Zingiberaceae I. Amomum in Lambir Hills, Sarawak. Edinburgh Journal
of Botany 55 (1): 45–64.
Shorthouse, D.P. (2010) SimpleMappr, an online tool to produce publication-quality point maps. Available from: http://www.simplemappr.
net (accessed 11 August 2020)
Smith, R.M. (1985) A review of Bornean Zingiberaceae: 1. (Alpineae p.p.). Notes from the Royal Botanic Garden, Edinburgh 42: 261–314.
Smith, R.M. (1986) A review of Bornean Zingiberaceae: 2. (Alpineae, concluded). Notes from the Royal Botanic Garden, Edinburgh
Thiers, B. (2018) [continuously updated] Index Herbariorum: A global directory of public herbaria and associated staff. New York Botanical
Garden’s Virtual Herbarium. Available from: http://sweetgum.nybg.org/science/ih/ (accessed 20 April 2020)