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Litostigma, a new genus from china: A morphological link between basal and derived didymocarpoid gesneriaceae

Authors:

Abstract

Litostigma, a new Chinese genus of Gesneriaceae, is described and illustrated. It is characterised by its large flowers in comparison to its small leaves; slightly revolute leaf margins; 1-flowered cymes; crateriform or disciform stigma; and long ovoid capsule. Rather surprisingly, Litostigma falls among the basal didymocarpoid Gesneriaceae. Two new species, Litostigma coriaceifolium Y.G.Wei, F.Wen & M.Möller and Litostigma crystallinum Y.M.Shui & W.H.Chen, are described.
E D I N B U R G H J O U R N A L O F B O T A N Y 67 (1): 161–184 (2010) 161
ÓTrustees of the Royal Botanic Garden Edinburgh (2010)
doi:10.1017/S0960428609990291
LITOSTIGMA, A NEW GENUS FROM CHINA: A
MORPHOLOGICAL LINK BETWEEN BASAL AND
DERIVED DIDYMOCARPOID GESNERIACEAE
YI-GANG WEI
1
,
4
,FANG WEN
1
,WEN-HONG CHEN
2
,
YU-MIN SHUI
2
&M.MO
¨LLER
3
,
4
Litostigma, a new Chinese genus of Gesneriaceae, is described and illustrated. It is
characterised by its large flowers in comparison to its small leaves; slightly revolute leaf
margins; 1-flowered cymes; crateriform or disciform stigma; and long ovoid capsule.
Rather surprisingly, Litostigma falls among the basal didymocarpoid Gesneriaceae. Two
new species, Litostigma coriaceifolium Y.G.Wei, F.Wen & M.Mo
¨ller and Litostigma
crystallinum Y.M.Shui & W.H.Chen, are described.
Keywords. Flora of China, Gesneriaceae, Litostigma,Petrocosmea, phylogeny.
Introduction
In the most recent classification of the Gesneriaceae (Weber, 2004) four informal
major groups were recognised. Of these the palaeotropical didymocarpoids include
85 genera, 58 of which are found in China. During an expedition to Guizhou
province, China, in 2007, specimens of a new species were collected (Fig. 1) which
also proved to belong to a new genus. In reference to its simple stigma the genus is
named Litostigma Y.G.Wei, F.Wen & M.Mo
¨ller. The species is named Litostigma
coriaceifolium Y.G.Wei, F.Wen & M.Mo
¨ller. Subsequently, it was discovered that
material of a species morphologically very similar to Litostigma coriaceifolium had
been collected in 2002 in Malipo, Yunnan (Fig. 1), and cited as ‘Petrocosmea
crystallina’ Y.M.Shui & W.H.Chen in Shui & Chen (2006). This name was not
validly published under the International Code of Botanical Nomenclature (McNeill
et al., 2006) as there was no Latin diagnosis or description. This plant was placed in
Petrocosmea Oliv. due to the form of the peduncle and its anther indumentum. In
some species of Petrocosmea and in ‘Petrocosmea crystallina’ the peduncles bend
back in order to place the capsule into rock crevices and thus the seeds into a suitable
position for seedling establishment (Shui Yu-Min, pers. obs.).
1
The Botanical Institute of Guangxi, Guilin 541006, China. E-mail: weiyigang@yahoo.com.cn
2
Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China.
3
Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh EH3 5LR, Scotland, UK. E-mail:
m.moeller@rbge.ac.uk
4
Authors for correspondence.
Generic delimitations in Gesneriaceae are often difficult due to large overlaps in
characters betweengenera (Burtt, 1963, 1977). For this reason we undertook a combined
phylogenetic–morphological approach. We attempted to determine the phylogenetic
position of Litostigma among the Old World didymocarpoid Gesneriaceae, specifically
in relation to Petrocosmea and other morphologically similar genera. In addition to the
molecular analysis a detailed morphological comparison was made.
Materials and Methods
Phylogenetic analysis
A data matrix was assembled consisting of 1952 molecular sequence characters
(trnLF 51054 characters, and ITS 5898 characters) that included 90 taxa across
the Old World didymocarpoids. Sequence data were either taken from Mo
¨ller et al.
(2009) or acquired using methods explained therein. Twenty-one sequences (16 ITS
and 5 trnLF) were newly acquired here, two were included from previous
publications (Jancaea heldreichii Boiss., Ramonda myconi (L.) Rchb., Mo
¨ller et al.,
1999), and one retrieved from GenBank (Haberlea rhodopensis Friv., Mo
¨ller &
Cronk, 2001a). The ingroup samples included Litostigma coriaceifolium,‘Petrocos-
mea crystallina’ and four species of Petrocosmea proper (Table 1). A partition
FIG.1. Map showing the collection localities of Litostigma coriaceifolium Y.G.Wei, F.Wen
& M.Mo
¨ller (s) and L. crystallinum Y.M.Shui & W.H.Chen ( ). Drawn with DIVA GIS 5.2
(http://www.diva-gis.org).
162 YI-GANG WEI ET AL.
TABLE 1. Details of 92 didymocarpoid taxa included in the phylogenetic analysis, including voucher number (information in square brackets
refers to the accession number of living material grown on from the specimen cited – where there is only a living accession number given it has
been vouchered into the herbarium with the same number), deposition of voucher, origin and GenBank sequence information. RBGE 5living
collection at the Royal Botanic Garden Edinburgh, Scotland, UK; HBV 5living collection at the Botanic Garden, Vienna, Austria
Taxon
Voucher
number
Deposited
in Origin trnLF ITS1/ITS2
Aeschynanthus bracteatus
Wall. ex DC.
Wang 991113 PE China, Yunnan,
Xichou county
FJ501501 –
Aeschynanthus bracteatus
Wall. ex DC.
R. Cherry 123 [cult. RBGE
19970165]
E Vietnam, Lao Cai AF349203/
AF349284
Aeschynanthus micranthus
C.B.Clarke
M. Moeller MMO 01-79 E, WU China, Yunnan,
Hekou county
FJ501500 –
Aeschynanthus micranthus
C.B.Clarke
A. Reid & J. Fernie 004
[cult. RBGE 19951561]
E China, Yunnan, Xishuangbanna
Dai Aut. Pref.
– AF349218/
AF349299
Agalmyla biflora (Elmer)
O.M.Hilliard & B.L.Burtt
RBGE-PNH1998-25435
[cult. RBGE 19980287]
E Philippines, Palawan, near
summit of Cleopatra
Needle
FJ501541 –
Agalmyla biflora (Elmer)
O.M.Hilliard &
B.L.Burtt
RBGE-PNH1998-25517
[cult. RBGE 19980292]
E Philippines, Palawan, near
Thumb Peak
– FJ501361
Agalmyla clarkei (Elmer)
B.L.Burtt
RBGE-PNH1999(P99) 13
[cult. RBGE 19991911]
E Philippines, Leyte, Leyte Island,
Mt. Lobi
FJ501540 –
Agalmyla clarkei (Elmer)
B.L.Burtt
RBGE-PNH1997 IS26
[cult. RBGE 19972530A]
E Philippines, Luzon, Barangay
Penicuason
– FJ501360
Anclystemon aureus (Franch.)
B.L.Burtt
M. Mo
¨ller MMO 01-153 E, WU China, Yunnan,
Binchuan county
FJ501505 FJ501336
Ancylostemon convexus Craib M. Mo
¨ller MMO 01-176 E, WU China, Yunnan, Dali county,
Yu Dai Lu, Cang Shan
FJ501506 FJ501337
Anna mollifolia (W.T.Wang)
W.T.Wang &
K.Y.Pan
M. Mo
¨ller MMO 01-146 E, WU China, Guangxi, Napo county FJ501543 AF055050/
AF055051
LITOSTIGMA, A NEW GENUS FROM CHINA 163
TABLE 1. (Cont’d)
Taxon
Voucher
number
Deposited
in Origin trnLF ITS1/ITS2
Anna submontana Pellegr. M. Mo
¨ller MMO 01-85 E, WU China, Yunnan, Maguan county FJ501542 FJ501362
Boea hygrometrica
(Bunge) R.Br.
Gu 01-6184 KUN China, unknown locality FJ501476 FJ501319
Boea magellanica Lam. Lambinon 87/830 L Papua New Guinea,
Morobe province
FJ501478 FJ501321
Boeica ferruginea Drake M. Mo
¨ller MMO 01-182B
ex Zhang Chang Qin 200012
E, WU China, SE Yunnan FJ501440 This study
Boeica porosa C.B.Clarke Gu 99-705 KUN China, unknown locality FJ501441 This study
Briggsia longipes (Hemsl.
ex Oliv.) Craib
M. Mo
¨ller MMO 01-122 E, WU China, Yunnan, Xichou county FJ501545 AF055052/
AF055053
Briggsia mihieri Craib Wang 11315B PE China, Chongqing, Nanchuan
county
FJ501544 FJ501363
Briggsia muscicola (Diels) Craib Kew (1995-2229) K Unknown origin FJ501548 FJ501366
Briggsia rosthornii (Diels)
B.L.Burtt
Sino-American Bryological
Expedition 1991,
no. 398 (US 229325)
US China, Guizhou, Jiangkou Xian FJ501547 FJ501365
Calcareoboea coccinea C.Y.Wu
ex H.W.Li
M. Mo
¨ller MMO 01-141 E, WU China, Guangxi, Napo county FJ501516 FJ501365
Chirita asperifolia (Blume)
B.L.Burtt
P. Woods 1071 (C6570) E Indonesia, Java, forest above
Tjibodas Garden
FJ501538 JF501359
Chirita caliginosa C.B.Clarke Ex HB Mu
¨nchen-Nymphenburg;
Kiehn & Pfosser 2000-1
[cult. HBV GS-96-02]
WU Peninsular Malaysia FJ501488 FJ501325
Chirita lavandulacea Stapf Cult. RBGE 20000897 E China FJ501487 FJ501324
Chirita pinnata W.T.Wang Expedition Beijing 896526
(US 294374)
US China, Guangxi, Rongshui Xian FJ501526 FJ501349
Chirita pinnatifida (Hand.-
Mazz.) B.L.Burtt
Xie Qingjian J-037 (US 422838) US China, Guangdong, Lianxian
county
FJ501527 FJ501350
164 YI-GANG WEI ET AL.
TABLE 1. (Cont’d)
Taxon
Voucher
number
Deposited
in Origin trnLF ITS1/ITS2
Chirita pumila D.Don Gaoligong Shan Expedition 1996
7938 [cult. RBGE 19962271]
E China, Yunnan, Nujiang Lisu
Aut. Pref., Fugong county
FJ501491 FJ501327
Chirita sinensis Lindl. T.C. Godfrey 369 [cult. RBGE
19791050]
E China, Hong Kong FJ501524 FJ501348
Chirita urticifolia Buch.-Ham.
ex D.Don
EMAK 109 H (Edinburgh-
Makalu Expedition 1991)
E Nepal, Sankhuwasabha
district, Arun valley
FJ501492 FJ501328
Chirita walkeri Gardner Skog 7736 (US 590934) [cult.
Smithsonian 94-250]
US Sri Lanka; leg. in US
11.03.1996
FJ501490 FJ501326
Chiritopsis repanda W.T.Wang
var. guilinensis W.T.Wang
Ex Smithsonian Institute 94-083
[cult. RBGE 19951206]
E China, Guangxi, Zhuang
Aut. Reg.
AJ492292 FJ501351
Conandron ramondioides
Sieb. & Zucc.
Takeda Herbal Garden Kyoto
[cult. RBGE 19691267]
E Japan FJ501515 FJ501340
Corallodiscus lanuginosus
(Wall. ex R.Br.) B.L.Burtt
M. Mo
¨ller MMO 01-138 E, WU China, Yunnan,
Xichou county
FJ501432 This study
Cyrtandra cupulata Ridl. Weber 840806-2/4 WU Peninsular Malaysia, Perak,
Maxwell’s Hill
FJ501532 AY818826/
AY818861
Cyrtandra glabra Banks
ex Gaertn.
Cronk & Percy T91 E French Polynesia: Society Is.:
Tahiti: Mt. Tearoa Col
AY423136 FJ501353
Cyrtandra longifolia (Wawra)
Hillebr. ex C.B.Clarke
Kiehn 920825-2/1 [cult. HBV] WU USA, Hawaii, Kauai FJ501531 AY818846/
AY818881
Cyrtandra pendula Blume Weber & Anthonysamy
860730-1/2 [cult. HBV]
WU Peninsular Malaysia FJ501530 FJ501354
Didymocarpus antirrhinoides
A.Weber
Jong 9009 [cult. RBGE
19650167]
E Peninsular Malaysia, Perak,
Bujong Melakah, Ipoh
FJ501513 DQ912671
Didymocarpus citrinus Ridl. P. Davis 69437 [cult. RBGE
19830510]
E Peninsular Malaysia, Perlis,
Kedat Peak
AJ492293 DQ912669
Didymocarpus cordatus Wall.
ex DC.
Weber 860816-2/1 WU Peninsular Malaysia, Perak,
Maxwell’s Hill
AJ492294 DQ912673
LITOSTIGMA, A NEW GENUS FROM CHINA 165
TABLE 1. (Cont’d)
Taxon
Voucher
number
Deposited
in Origin trnLF ITS1/ITS2
Didymocarpus podocarpus
C.B.Clarke
Noltie, Pradhan, Sherub &
Wangdi 193
E Bhutan, Deothang district FJ501514 DQ912688
Didymocarpus purpureobracteatus
W.W.Sm.
Wang 991106 PE China, Yunnan,
Pingbian county
FJ501510 –
Didymocarpus purpureobracteatus
W.W.Sm.
M. Mo
¨ller MMO 01-70 E, WU China, Yunnan,
Pingbian county
– DQ912676
Didymocarpus stenanthos
C.B.Clarke
M. Mo
¨ller MMO 01-156 E, WU China, Yunnan,
Binchuan county
FJ501512 DQ912687
Dolicholoma jasminiflorum
D.Fang & W.T.Wang
M. Mo
¨ller MMO 09-06851 E China, Guangxi, Napo county This study This study
Haberlea rhodopensis Friv. Cult. RBGE 19754106 E (Greece) AJ492296 Mo
¨ller &
Cronk,
2001a
Hemiboea bicornuta (Hayata)
Ohwi
Smithsonian Institute [cult.
RBGE 19951207]
E Unknown origin FJ501534 FJ501356
Hemiboea cavaleriei H.Le
´v. Gu G3 KUN China, unknown locality FJ501533 FJ501355
Hemiboea gracilis Franch. Wang 11317 PE China, Chongqing,
Nanchuan county
FJ501536 This study
Hemiboea subcapitata
C.B.Clarke
Wang 11306 PE China, Chongqing,
Chengkou county
FJ501535 FJ501357
Jancaea heldreichii Boiss. E.G. Cairns [cult. RBGE
19771605]
photo E Greece, Mt. Olympus FJ501439 Mo
¨ller
et al., 1999
Kaisupeea herbacea
(C.B.Clarke) B.L.Burtt
K. Larsen 44272 [cult. RBGE
19972918]
E Thailand, Chachoengsao
province, Khao Tak Groep
FJ501459 FJ501309
Leptoboea multiflora
(C.B.Clarke) Gamble subsp.
grandifolia B.L.Burtt
Larsen et al. 32065 E Thailand, SE, Khaso Phra Bat,
N of Chanthaburi
FJ501442 This study
166 YI-GANG WEI ET AL.
TABLE 1. (Cont’d)
Taxon
Voucher
number
Deposited
in Origin trnLF ITS1/ITS2
Litostigma coriaceifolium
Y.G.Wei, F.Wen &
M. Mo
¨ller, sp. nov.
M. Mo
¨ller MMO 07-1162 E, IBK China, Guizhou, Xingyi county This study This study
Litostigma crystallinum
Y.M.Shui & W.H.Chen,
sp. nov.
Y.M. Shui 43865 KUN China, Yunnan, Malipo county This study This study
Loxostigma fimbrisepalum
K.Y.Pan
Wang 991005 PE China, Yunnan, Jinping county FJ501507 This study
Loxostigma griffithii (Wight)
C.B.Clarke
Kew/Edinburgh Kanchenjunga
Expedition (1989) 940
[cult. RBGE 19892473A]
E Nepal, Yamphudin FJ501508 FJ501338
Lysionotus chingii Chun
ex W.T.Wang
Wang S-10669 PE China, unknown locality FJ501498 FJ501332
Lysionotus forrestii W.W.Sm. Gaoligong Shan Expedition
1996 7925 [cult. RBGE
19962269A]
E China, Yunnan, Nujiang
Lisu Aut. Pref.
FJ501495 AF349152/
AF349233
Lysionotus pauciflorus Maxim. M. Mo
¨ller MMO 01-101 E, WU China, Yunnan, Xichou county,
Cheng Jia Po
FJ501497 FJ501331
Opithandra primuloides (Miq.)
B.L.Burtt
T. Tsuzuki [cult. RBGE
19842178A]
E Japan, unknown locality FJ501546 FJ501364
Oreocharis auricula (S.Moore)
C.B.Clarke
Sino-American Bryological
Expedition 1991, no. 1832
WU China, Guizhou, Yinjiang
county
FJ501481 –
Oreocharis auricula (S.Moore)
C.B.Clarke
M. Mo
¨ller MMO 03-304 E China, Guizhou, Jiangkou
county
– FJ501323
Ornithoboea arachnoidea (Diels)
Craib
Ex HBV [cult. RBGE 19972903] E Thailand, Chiang Mai, Doi
Chiang Dao
FJ501461 FJ501312
Ornithoboea wildeana Craib Wang 00401 PE China, Yunnan, Xichou county FJ501462 FJ501313
LITOSTIGMA, A NEW GENUS FROM CHINA 167
TABLE 1. (Cont’d)
Taxon
Voucher
number
Deposited
in Origin trnLF ITS1/ITS2
Paraboea acutifolia (Ridl.)
B.L.Burtt
Weber 86805-2/1 WU Peninsular Malaysia, Kedah,
Pulau Langkawi, Bukit
Terbak
FJ501464 FJ501314
Paraboea capitata Ridl. Weber 870522-5/2 [cult. HBV] WU Peninsular Malaysia, Perak,
Kinta district
AJ492298 FJ501315
Paraboea crassifolia (Hemsl.)
B.L.Burtt
M. Mo
¨ller MMO 01-83 E, WU China, Yunnan, Maguan
county
FJ501472 FJ501318
Paraboea rufescens (Franch.)
B.L.Burtt var. umbellata
(Drake) K.Y.Pan
M. Mo
¨ller MMO 01-147 E, WU China, Guangxi, Napo county,
Nong Bu
FJ501470 FJ501317
Paralagarosolen fangianum
Y.G.Wei
M. Mo
¨ller MMO 07-1168 E China, Guangxi, Napo county This study This study
Petrocodon dealbatus Hance Xie Qingjian J-042 (US 422841) US China, Guangdong, Lianxian
county
FJ501537 FJ501358
Petrocosmea kerrii Craib Cult. RBGE 19715592 E Unknown origin FJ501502 FJ501334
Petrocosmea minor Hemsl. Sino-American Bot. Exped.
1984, no. 1574 (US 56119)
US China, Yunnan, Lunan Xian FJ501504 This study
Petrocosmea nervosa Craib Smithsonian Institute 78-057
[cult. RBGE 19933232]
E, US China, N Yunnan AJ492299 FJ501335
Petrocosmea sericea C.Y.Wu
ex H.W.Li
Gu 99-1104 KUN China, unknown locality FJ501503 This study
Platystemma violoides Wall. Projektteam 197-241 WU Nepal, SE Kathmandu
Pulchoki
FJ501443 This study
Primulina tabacum Hance Q.J. Xie & C.X. Ye [cult.
RBGE 19951540]
E China, Guangdong,
Lian River
AJ492300 FJ501352
Ramonda myconi (L.) Rchb. Lausanne Botanic Garden
[cult. RBGE 19711477]
E Spain, Pyrenees AJ492301 Mo
¨ller et al.,
1999
168 YI-GANG WEI ET AL.
TABLE 1. (Cont’d)
Taxon
Voucher
number
Deposited
in Origin trnLF ITS1/ITS2
Raphiocarpus begoniifolius
(H.Le
´v.) B.L.Burtt
Wang 991108 PE China, Yunnan, Yuanyang
county
FJ501517 FJ501342
Raphiocarpus petelotii (Pellegr.)
B.L.Burtt
S. Goodwin & R. Cherry
92/208 [cult. RBGE
19982405]
E Vietnam, Lao Cai province FJ501518 FJ501343
Rhabdothamnopsis sinensis
Hemsl.
[Ex cult. Kew 1988 4866] K China, unknown locality AJ492302 FJ501310
Rhynchotechum discolor
(Maxim.) B.L.Burtt
RBGE-PNH Expedition
1997/SM8 [cult. RBGE
19972562]
E Philippines, Luzon, Isabela FJ501436 This study
Rhynchotechum parviflorum
Blume
M. Mendum, G. Argent &
Hendrian 00148
E Central Sulawesi, Mt. Sojol FJ501437 This study
Saintpaulia tongwensis
B.L.Burtt
I.C. Mather 2
[cult. RBGE 19850668]
E Tanzania, Tanga region FJ501446 FJ501303
Saintpaulia velutina
B.L.Burtt
Munich University [cult.
RBGE 19872179]
E Tanzania, unknown locality AJ492303 FJ501304
Spelaeanthus chinii Kiew,
A.Weber & B.L.Burtt
Weber 860709-2/2 WU Peninsular Malaysia, Pahang,
Jerantut district, Taman
Negara
FJ501457 FJ501307
Streptocarpus andohahelensis
Humbert
M. Mo
¨ller MM 9717 E Madagascar, Tule
´ar,
Ranomafana
FJ501449 AF316903
Streptocarpus beampingaratrensis
Humbert
M. Mo
¨ller MM 9715 E Madagascar, Tule
´ar,
Ranomafana
FJ501448 AF316905
Streptocarpus dunnii Hook.f. Isobel La Croix
[cult. RBGE 19941745]
E Swaziland, Mbabane FJ501456 AF316951
Streptocarpus hilsenbergii R.Br. B.L. Burtt [cult. RBGE
19631505]
E Madagascar, Mandrake valley FJ501450 AF316907
LITOSTIGMA, A NEW GENUS FROM CHINA 169
TABLE 1. (Cont’d)
Taxon
Voucher
number
Deposited
in Origin trnLF ITS1/ITS2
Streptocarpus holstii Engl. Cornell University (Bail. Hort.)
[cult. RBGE 19592272]
E Tanzania, unknown locality AJ492304 AF316917
Streptocarpus ibityensis
Humbert
E. Fischer 250/93 [cult. RBGE
19932867]
E Madagascar, Antananarivo FJ501455 AF316926
Streptocarpus papangae
Humbert
M. Mo
¨ller MM 9718 E Madagascar, Tule
´ar,
Ranomafana
FJ501444 AF316929
Streptocarpus rexii Lindl. K. Jong [cult. RBGE 19870333] E South Africa, NE Cape,
Grahamstown
AJ492305 AF316979
Streptocarpus saxorum
Engl.
Chautems & Perret 01-023 G Cult. CJBG FJ501447
Streptocarpus saxorum
Engl.
I.C. Mather 4 [cult. RBGE
19721499]
E Tanzania, Tanga region AF316914
Wentsaiboea renifolia
D.Fang & D.H.Qin
M. Mo
¨ller MMO 06-791 E China, Guangxi, DuAn county This study This study
170 YI-GANG WEI ET AL.
homogeneity test and the parsimony and branch support analyses were conducted
following Mo
¨ller et al. (2009). The phylogenetic tree was rooted on Corallodiscus
Batalin as one of the most basal lineages in Old World didymocarpoids, as suggested
in Mo
¨ller et al. (2009).
Scanning electron microscopy
Materials for SEM were fixed in FAA (5% acetic acid, 5% formaldehyde, and in 50%
ethanol). The fixed material was dehydrated in an ethanol series and acetone, critical
point dried in CO
2
with an Emitech K850 critical point dryer (Ashford, UK), coated
with platinum in a peltier cooled Emitech K575X sputter coater (Ashford, UK) and
then examined with a LEO Supra 55VP scanning electron microscope at a working
distance of 11 mm and 4.8 to 5 kV.
Results and Discussion
Comparison with morphologically similar genera
Litostigma has the characteristic morphological features of relatively large diandrous
flowers in comparison to the small leaves and stature of the plant, with petiolate,
slightly revolute leaf margins, uniflowered cymes, undivided stigma and untwisted
narrowly ovoid capsules, dehiscing loculicidally and septicidally.
Among Weber’s (2004) Old World advanced Asiatic and Malesian didymocarpoid
genera there are some morphological similarities between Litostigma and straight-
fruited advanced genera such as Didymocarpus Wall., Dolicholoma D.Fang &
W.T.Wang, Paralagarosolen Y.G.Wei, Petrocodon Hance and Wentsaiboea D.Fang
& D.H.Qin. The similarities are often in individual characters that are, however,
shared with several other genera, such as a 6capitate stigma (Didymocarpus,
Dolicholoma,Petrocodon,Wentsaiboea), small elliptic leaves, ovoid ovary and capsule
(Dolicholoma,Paralagarosolen,Wentsaiboea), and 1-flowered cymes (Dolicholoma,
Paralagarosolen). However, these genera differ from Litostigma in other characters
(Table 2). For example, most of them have verruculose and/or ornamented seed testa
cells (Table 2; Beaufort-Murphy, 1983), very unlike Litostigma (Fig. 3A–B).
Litostigma differs from Petrocosmea most notably through the latter’s short tube
and flat-faced corollas, and its strongly ornamented seeds (Table 2). Petrocosmea
flowers are also distinctly bilabiate, with the lobes of the upper lip often nearly
completely fused.
Phylogenetic position of Litostigma
The partition homogeneity test suggested that the two sequence matrices were highly
congruent (P50.74). Analysing the two genes individually did not alter the position
of Litostigma and Petrocosmea proper in the phylogenetic trees (data not shown).
LITOSTIGMA, A NEW GENUS FROM CHINA 171
TABLE 2. Morphology of selected Gesneriaceae genera superficially resembling Litostigma or implicated in molecular studies (compiled from
Beaufort-Murphy, 1983; Wang et al., 1990, 1998; Wei, 2004; Weber,2004; and Weber & Skog, 2007 onwards)
Character
Genus
Number of
flowers per
inflorescence Flower Stamens Stigma Ovary Capsule Seeds
Litostigma 1-flowered Infundibuliform 2, anterior,
coherent
adaxially
Crateriform or
disciform
Ovoid, 1-loculed,
placentae 2,
parietal, slightly
protruding
inwards, 2-cleft
Straight in relation to
pedicel, slightly longer
than calyx, long
narrowly ovoid,
dehiscing to base,
4 valves
Reticulate
Petrocosmea Few- to
several-
flowered
Short-tubed,
flat-faced
2, anterior,
basifixed,
coherent
at apices
Capitate or
globose
Ovoid or
conical
Straight in relation to
pedicel, ovoid or
oblong, dehiscing
loculicidally, straight
Ornamented
Dolicholoma 1- to
4-flowered
Near
hypocrateriform
2, anterior,
coherent
adaxially
Terminal,
disc-like,
undivided
Narrowly ovoid,
1-loculed,
placentae 2,
parietal, slightly
protruding
inwards, 2-cleft
Straight in relation to
pedicel, nearly as long
as calyx, narrowly
ellipsoid, dehiscing to
base, 4 valves, straight
Verruculose,
complex
ornamented
Paralagarosolen 1-flowered Hypocrateriform 2, anterior,
coherent
adaxially
Bilobed, equal,
lobes broadly
ovoid (unclear
whether split
horizontally)
Ovoid to near
ellipsoid,
1-loculed,
placentae 2,
parietal,
projecting
slightly inwards,
2-cleft
Straight in relation to
pedicel, slightly
longer than calyx,
ovoid-ellipsoid,
dehiscing to base,
4 valves, straight
Densely
verrucose
172 YI-GANG WEI ET AL.
TABLE 2. (Cont’d)
Character
Genus
Number of
flowers per
inflorescence Flower Stamens Stigma Ovary Capsule Seeds
Petrocodon Few- to
many-
flowered
Suburceolate-
tubular,
campanulate
2, anterior,
anthers
dorsifixed,
coherent
apically,
dehiscing
longitudinally
Terminal, nearly
globose,
undivided
Linear, 1-loculed,
placentae 2,
parietal,
projecting
inwards, 2-cleft
Straight in relation to
pedicel, much
surpassing calyx,
linear, dehiscing
loculicidally to base,
2 valves, straight
Verruculose,
smooth
Wentsaiboea Few- to
many-
flowered
Obliquely
campanulate,
swollen
abaxially
2, anterior,
anthers
dorsifixed,
coherent
adaxially,
dehiscing
longitudinally
Obliquely
hippocrepiform
Narrowly ovoid,
1-loculed,
placentae 2,
parietal,
projecting
inwards, 2-cleft
Straight in relation to
pedicel, slightly longer
than calyx, narrowly
ellipsoid, straight
Verruculose,
ornamented
Didymocarpus 1- to many-
flowered
Cylindric to
infundibuliform-
tubular, wide to
narrow, long,
rarely saccate at
base
2, anterior,
anthers
dorsifixed,
coherent
adaxially,
dehiscing
longitudinally
Terminal,
depressed-
globose to
disc-like or
truncate
Linear, 1-loculed,
placentae 2,
parietal, slightly
projecting
inwards, 2-cleft
Straight in relation to
pedicel, much longer
than calyx, usually
linear, dehiscing
loculicidally to base,
2 or 4 valves, straight
Striate,
tuberculate,
verrucate,
or smooth
LITOSTIGMA, A NEW GENUS FROM CHINA 173
TABLE 2. (Cont’d)
Character
Genus
Number of
flowers per
inflorescence Flower Stamens Stigma Ovary Capsule Seeds
Corallodiscus 1- to many-
flowered
Short tubular 4, anthers
dorsifixed,
coherent in
pairs,
dehiscing
longitudinally
Terminal,
capitate,
emarginate
Oblong,
1-loculed,
placentae 2,
parietal,
projecting
inwards, 2-cleft
Straight in relation to
pedicel, much longer
than calyx, narrowly
oblong to linear,
rarely ovoid, dehiscing
loculicidally and
sometimes septicidally
to base, 2 valves,
straight
Reticulate
Haberlea Few-
flowered
Short cylindric,
broad
4, didynamous Capitate Ovoid,
1-loculed,
placentae 2,
parietal,
projecting
inwards,
2-cleft
Ovoid, dehiscing
septicidally,
2 valves
Reticulate
Ramonda 2- to 4-
flowered
Absent,
actinomorphic
corolla
4–5, equalling
the number of
corolla lobes
Capitate Ovoid,
1-loculed,
placentae 2,
parietal,
projecting
inwards,
2-cleft
Ovoid, dehiscing
septicidally,
2 valves
Reticulate
174 YI-GANG WEI ET AL.
The maximum parsimony (MP) analysis on the combined sequences resulted in
156 most parsimonious trees of 3957 steps (CI 50.4079, RI 50.6363). The topology
recovered here is congruent with that in Mo
¨ller et al. (2009). Here we focus on the
positions of Litostigma and ‘Petrocosmea crystallina’ in particular.
The MP strict consensus tree shows the new genus Litostigma and ‘Petrocosmea
crystallina’ (in Fig. 2 as L. crystallinum) in a strongly supported sister relationship
FIG.2. Strict consensus tree of 156 most parsimonious trees based on trnLF and ITS
sequences, highlighting the position of Litostigma coriaceifolium,L. crystallinum and
Petrocosmea, falling in two very distantly related clades. Numbers along branches are
bootstrap values. Asterisks denote branches that received less than 50% branch support.
LITOSTIGMA, A NEW GENUS FROM CHINA 175
(BS 5100%). Their genetic distance is 0.36% in the trnLF and 3.7% in the ITS data,
indicating their close relatedness. Intrageneric ITS distance levels in other Gesner-
iaceae genera are much higher than those observed between Litostigma and
Petrocosmea crystallina’ (e.g. Aeschynanthus Jack: 16.9%, Denduangboripant et al.,
2001; Agalmyla Blume: 14.1%, Chapman, 2003; Streptocarpus Lindl.: 23.5%, Mo
¨ller
& Cronk, 2001a, 2001b) and thus support a treatment of ‘Petrocosmea crystallina’as
a species of the new genus Litostigma (described as L. crystallinum below).
In the present phylogeny the clade with Petrocosmea proper (with 4 out of c.27
species included in the analysis – representing all three sections recognised in the
genus) was highly supported (BS 5100%) and is sister to a grade of Raphiocarpus
begoniifolius (H.Le
´v.) B.L.Burtt and R. petelotii (Pellegr.) B.L.Burtt with high
branch support (BS 598%). The Litostigma clade is far from Petrocosmea proper,
near the base of the didymocarpoids, on a polytomy with the European Ramonda
Rich./Jancaea Boiss. clade. This suggests that the true affinities of Litostigma do not
necessarily lie directly with the European genera.
Though some branches in the phylogenetic tree between Petrocosmea proper and
Litostigma are not well supported, two were highly supported – one leading to the
straight-fruited advanced Asiatic and Malesian clade (BS 592%), the other
supporting the monophyly of the former clade plus the two twisted-fruited clades,
the African/Madagascan and the twisted-fruited advanced Asiatic and Malesian
clade (BS 591%). This makes a closer relationship between Petrocosmea proper and
Litostigma highly unlikely.
The genera with some morphological similarities to Litostigma, namely Dolicho-
loma,Paralagarosolen,Petrocodon,Wentsaiboea and Didymocarpus, are all distant
from the new genus in a mixed clade (BS 5100%) (first four genera), or in a separate
clade with Chirita asperifolia (Blume) B.L.Burtt (BS 597%) (Didymocarpus), among
the straight-fruited advanced Asiatic and Malesian genera (BS 595%), and on
a polytomy with the clade containing Petrocosmea.
Litostigma as a morphological link
Litostigma is a new genus, currently with just two species. A relationship to the basal
Asiatic and European genera of Old World Gesneriaceae is suggested by molecular
data. A loose association with Ramonda and Jancaea is indicated, but there is no
obvious similarity in gross morphology. Apart from its overall smaller size,
Litostigma has strongly petiolate and glabrous leaves, very unlike Ramonda and
Jancaea. Furthermore, the corolla of Litostigma is strongly tubular and bilabiate,
with two fertile stamens, while Ramonda has a 5-merous, actinomorphic and flat-
faced flower with five stamens, and Jancaea has a 4-(rarely 5-)merous, subactino-
morphic and campanulate flower with 4 (rarely 5) stamens.
Among the basal didymocarpoid lineages Weber (2004) does not list any genera
with morphological similarities to Litostigma; in fact it is the only genus with two
176 YI-GANG WEI ET AL.
fertile stamens in this group, all others having four or five (an exception is
Tetraphyllum which includes species with both four and two stamens; Weber,
2004). Apart from tetrandry, the basal didymocarpoids are characterised by the
possession of seeds without testa cell ornamentation, straight fruits (Weber, 2004;
Mo
¨ller et al., 2009) and septicidal (Haberlea Friv., Jancaea and Ramonda)or
septicidally and loculicidally (Boeica C.B.Clarke, Corallodiscus and Leptoboea
Benth.) dehiscing capsules. These seed, fruit shape, and capsule dehiscence (septi-
cidally and loculicidally) characters are also found in Litostigma (Fig. 3, Table 2).
A major morphological progression has taken place between basal didymocarpoid
lineages and the African, Madagascan and advanced Asian and Malesian lineages:
the evolution of twisted fruits (found in a major clade of the advanced Asian and
Malesian clade) and a change to diandry (Weber, 2004; Mo
¨ller et al., 2009). The
diandrous infundibuliform corolla of Litostigma is remarkably similar to those of
some species in the African genus Streptocarpus and the only difference of this genus
to Litostigma is the ovoid ovary and straight fruit of the latter. Such fruits are found
in some African genera, such as Saintpaulia Wendl. and Acanthonema Hook.f., and
represent cases of parallel convergent evolution within the genus Streptocarpus
(Mo
¨ller et al., 2009). Several other advanced Asiatic and Malesian genera possess
an infundibuliform diandrous corolla (some Chirita Buch.-Ham. ex D.Don,
FIG.3. Litostigma. A–C: Litostigma coriaceifolium. A, SEM micrograph of seed (scale bar 5
100 lm). Magnified in B (scale bar 510 lm). C, single bract subtending the single flower (scale
bar 5200 lm). D: Litostigma crystallinum, SEM micrograph of anthers (scale bar 51 mm).
LITOSTIGMA, A NEW GENUS FROM CHINA 177
Didymostigma W.T.Wang, some Lysionotus D.Don species, Pseudochirita
W.T.Wang, some Raphiocarpus Chun species and the twisted-fruited Rhabdotham-
nopsis Hemsl.), suggesting some convergence for this character in the evolution of
didymocarpoid Gesneriaceae.
In the present study the molecular data are the strongest support for the new genus
status of Litostigma. The morphological characters describing the species would
individually not make such a strong case, due to many overlaps with other genera.
Only the combination of a range of floral (infundibuliform flowers, diandry,
uniflowered inflorescence, undivided stigma, not twisted loculicidally and septicidally
dehiscing fruit) and vegetative (petiolate leaves with revolute leaf margin) characters
provides a unique definition of the genus.
The phylogenetic placement of Litostigma and the combination of ancestral and
derived characters within the didymocarpoid Gesneriaceae makes this genus a very
important morphological link between the ancestral basal Asiatic and European and
derived African, Asian and Malesian genera. The addition of further, as yet possibly
undiscovered, genera, particularly those in basal lineages, may help place Litostigma
more precisely. Further additions may also help stabilise phylogenetic relationships
among the basal and derived didymocarpoid lineages and help form a better
understanding of the morphological transitions involved in the evolution of the
majority of the Old World Gesneriaceae.
Taxonomic Treatment
Litostigma Y.G.Wei, F.Wen & M.Mo
¨ller, gen. nov. (subfam. Didymocarpoideae
Endl., tribe Didymocarpeae Endl.).
Petrocosmea Oliv. affinis a qua cyma 1-flora, stigmate crateriformi vel disciformi,
differt. A Dolicholomate D.Fang & W.T.Wang forma floris et seminibus reticulatis
(in Dolicholomate verruculosis et ornamentatis) differt.
Herbae perennes acaules rhizomatosae. Folia basalia petiolata. Cymae axillares
uniflorae, unibracteatae et bibracteate. Calyx actinomorphus. Sepala 5. Corollae
tubus infundibularis, abaxialiter paulo ventricosus, limbus bilabiatus, labio adaxiali
2-partito eo abaxiali 3-lobo omnibus cum lobis orbiculari-ovatis. Stamina 2 ad
laterem abaxialem corollae tubi adnata; filamenta linearia; antherae cohaerentes
ellipticae, subtilis puberulae (ampliare c.403). Staminodia 3 ad laterem adaxialem
corollae tubi adnata, linearia. Discus annularis. Pistillum inclusum; ovarium anguste
ovoideum, uniloculare, placentis duabus parietalibus intrinsecus projectis bifidis;
stylus elongatus ovario fere 4-plo longior; stigma simplex, crateriforme vel dis-
ciforme. Capsula ovoidea valvis quatuor dehiscens. – Typus generis: Litostigma
coriaceifolium Y.G.Wei, F.Wen & M.Mo
¨ller.
Perennial, stemless, rhizomatous herbs. Leaves basal, distinctly petiolate. Cymes
1-flowered, 1-bracteate. Sepals 5. Corolla zygomorphic, infundibuliform, adaxial lip
178 YI-GANG WEI ET AL.
2-parted, abaxial lip 3-parted, all lobes divided nearly to the base, orbicular-ovate.
Stamens 2, staminodes 3. Disc annular, ovary ovoid-ellipsoid, 1-loculed; placentae 2,
parietal, intrusive, bifid. Stigma crateriform or disciform. Fruit narrowly ovoid,
glabrous, dehiscing into 4 valves. Seeds reticulate, with raised testa cell walls.
Distribution. Southern China.
Etymology. The generic name is derived from Greek litos, meaning plain or simple,
and stigma in allusion to the uncomplicated structure of the stigma.
Litostigma coriaceifolium Y.G.Wei, F.Wen & M.Mo
¨ller, sp. nov. Figs 1, 3A–C, 4.
Haec species Litostigmati crystallino Y.M.Shui & W.H.Chen similis, sed foliis
majoribus 1–2.1 cm longis (in illa minoribus 4.5–6 cm longis), sepalis 3–4 mm (nec
7 mm) longis, antheris glabris (nec dense pilosis) et stigmate crateriformi (nec
disciformi) differt. – Type: China, Guizhou province, Xingyi county, Maling
gorge, 1186 m, 24 iv 2007, Y.G. Wei & F. Wen 0701 (holo IBK!; iso PE!).
Small perennial, stemless herb. Rhizome subterete, 1–1.5 cm long, 1–2 mm in
diameter. Leaves 10–15, basal; leaf blade coriaceous, elliptic, 1–2.1 cm long, 0.6–
1.1 cm wide, apex rounded, base obtuse to acute, margin entire, slightly revolute,
glabrous, 3–4-nerved on each side, lateral nerves not distinct when dried; petiole 0.4–
2.5 cm long, sparsely pubescent. Cymes 1–4, 1-flowered; peduncle 1.5–2 cm long,
together with pedicel pubescent; 1-bracteate, lanceolate-linear, 1.5–2 mm long,
margin entire, pubescent on each side; pedicel 1–4 cm long. Sepals 5, lanceolate to
narrowly ovate, 3–4 mm long, 1–1.5 mm wide, pubescent outside, glabrous inside.
Corolla light bluish-purple to pink, 1.2–2.1 cm long, pubescent outside, glabrous
inside, tube infundibuliform, with undilated proximal part 0.8–0.9 cm long and
dilated distal part 0.5–0.6 cm long, 1.5–1.7 cm in diameter at the orifice, 4–6 mm in
diameter near the base; adaxial lip 4–5 mm long, 2-parted nearly to the base, abaxial
lip 4–5 mm long, 3-parted nearly to the base, with lobes all orbicular-ovate. Stamens
2 (in anterior position), inserted at 5–7 mm from corolla tube base; filaments linear,
slightly arcuate, 3–4 mm long; anthers elliptic, 1–1.5 mm long, finely pubescent (at
403), coherent adaxially. Staminodes 3, glabrous, inserted at 4–6 mm from corolla
tube base, lateral 2 c.2 mm long, median c.1 mm long. Disc annular, c.1 mm high.
Pistil c.1.5 cm long; ovary ovoid-ellipsoid, c.2 mm long, c.1 mm in diameter,
narrowly ovoid with style pubescent, style c.1.3 cm long. Ovary 1-loculed; placentae 2,
parietal, intrusive, bifid. Stigma crateriform, c.2 mm in diameter. Fruit 5–6 mm long,
narrowly ovoid, glabrous, dehiscing into 4 valves. Seeds reticulate with raised testa cell
walls, 0.43 30.16 mm.
Distribution and habitat. As far as known endemic to Guizhou (Fig. 1). Found in the
Maling gorge, Xingyi county, Guizhou province, China, growing on rocky slopes.
Because of the wet limestone habitat, chalk grains cover the surface of the leaves.
LITOSTIGMA, A NEW GENUS FROM CHINA 179
Etymology. The epithet is derived from the coriaceous leaf blades in living material.
Conservation assessment. In 2006, the species was collected for the first time. In 2007
this locality was destroyed by a landslide. In 2008, a new locality was found about
38 km distant from the first, with about 3000 plants.
Proposed IUCN status. Critically Endangered, CR B1ac(iii).
FIG.4. Litostigma coriaceifolium Y.G.Wei, F.Wen & M.Mo
¨ller. A, habit; B, corolla open
with stamens and staminodes; C, stamens, calyx and pistil; D, capsule; E, ovary; F, capsule
and calyx. Drawn by Shun-Qing He.
180 YI-GANG WEI ET AL.
Litostigma crystallinum Y.M.Shui & W.H.Chen, sp. nov. Figs 1, 3D, 5.
Haec species Litostigmati coriaceifolio Y.G.Wei, F.Wen & M.Mo
¨ller similis, sed
foliis majoribus 4.5–6 cm longis (in illa minoribus 1–2.1 cm longis), sepalis 7 mm
(nec 3–4 mm) longis, antheris dense pilosis (nec glabris) et stigmate disciformi (nec
crateriformi) differt. Type: China, Yunnan province, Malipo county, Tianbao
village, 850 m, 4 v 2005, Y.M. Shui, W.H. Chen & M.D. Zhang 53856 (holo KUN!).
FIG.5. Litostigma crystallinum Y.M.Shui & W.H.Chen. A, habit; B, corolla open with
stamens and staminodes; C, calyx and pistil; D, stamens; E, capsule. Drawn by Wang Ling.
LITOSTIGMA, A NEW GENUS FROM CHINA 181
Perennial herb, stemless. Rhizome subterete, 3–5 mm long, 2–3 mm in diameter.
Leaves 11–13, basal; leaf blade thickly papery, elliptic, 4.5–6 cm long, 3–4 cm wide,
apex rounded, base broadly cuneiform, margin entire, slightly revolute, glabrous,
green above, greyish green beneath; lateral nerves distinct, 5–6 on each side, concave
above, convex beneath; petiole 4–11 cm long, glabrous. Cymes 1–2, 1-flowered;
peduncle 3–9 cm long, pubescent; 2-bracteate, small, lanceolate, 3 30.8 mm;
pedicel 2.5 cm long, pubescent. Sepals 5, lanceolate, c.0.7 30.2 cm, pubescent
outside, glabrous inside. Corolla purple, infundibuliform, 1.5–1.7 mm long, slightly
pubescent outside, glabrous inside; corolla tube 0.7–1 cm long with short proximal
undilated part; adaxial lobes 2, rather oblong, 0.7 30.6 cm, abaxial lobes 3, oblong
or obovate, 0.7 30.6 cm. Stamens 2 in anterior position, adnate to 3 mm above base
of corolla tube; filaments linear, slightly erect, c.4 mm long; anthers elliptic, c.2 mm
long, pilosous, coherent adaxially. Staminodes 2, 1–2.5 mm long, glabrous, adnate to
c.2–3 mm above corolla base. Disc annular. Pistil c.1.2 mm long; ovary ovoid-
ellipsoid, c.1.5 mm long, c.1 mm in diameter, 1-loculed with 2 parietal and intrusive
placentae; style c.9.5 mm long, pubescent. Stigma disciform, c.0.5 mm in diameter.
Fruit 4–5 mm long, narrowly ovoid, glabrous, dehiscing into 4 valves. Seeds ovoid,
obliquely reticulate with raised testa cell walls, 0.3 30.1 mm.
Paratypes. CHINA.Yunnan: Malipo county, Tianbao village, 850 m, 19 ix 2002, dry fruit, Y.M.
Shui & D.G. Wang 21814 (KUN); ibid., 1 ii 2005, Y.M. Shui & W.H. Chen 43865 (KUN).
Distribution and habitat. The new species is endemic to SE Yunnan, China (Fig. 1). It
grows on a cliff at the entrance of a limestone cave at c.850 m elevation. Because of
its close proximity to Vietnam, the species may occur there as well.
Etymology. The epithet crystallinum alludes to its habit (i.e. growing on crystalline
limestone).
Conservation assessment. The species was first found in November 2002, growing on
moist rock surfaces at the mouth of a limestone cave near a waterfall. The cave
occupied an area of c.2.5 32 m. Only 18 mature individuals and about 180 juvenile
plants were observed. In February 2005, only 16 mature and about 160 young plants
were found. In 2008, the status of the population was 14 mature and 130 immature
individuals, showing a slow but steady decline.
Proposed IUCN status. Critically Endangered, CR B1ab(v)+C2a(i)+D.
Acknowledgements
We thank Prof. Wen-Tsai Wang (Chinese Academy of Sciences) for his comments
on the paper; Shun-Qing He, Botanical Institute of Guangxi, Academia Sinica, for
Fig. 4; Wang Ling, Kunming Institute of Botany, Chinese Academy of Sciences, for
Fig. 5; Carmen Puglisi (E) for providing SEM images; and particularly Dr R. Mill
(Royal Botanic Garden Edinburgh) for taxonomic and editorial input. We should
182 YI-GANG WEI ET AL.
also like to thank the two anonymous reviewers for their constructive comments on
the manuscript. The National Geographical Society is thanked for their financial
support to S.Y.M. (NGS 8288-07). W.Y.G. received financial support from the
Royal Horticultural Society and the Sibbald Trust of the RBGE. The RBGE is
supported by the Scottish Government Rural and Environment Research and
Analysis Directorate (RERAD).
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Received 9 September 2009; accepted for publication 27 November 2009
184 YI-GANG WEI ET AL.
... Wei, F.Wen & M.Möller. It was confirmed and published using classical taxonomy, palynology, and phylogenetic analysis (Wei et al. 2010). Since then, some redefined genera, such as Hemiboea Clarke (Weber et al. 2011a), Loxostigma Clarke (Möller et al. 2014), Oreocharis , Paraboea (Clarke) Ridley (Puglisi et al. 2011), Petrocodon Hance (Weber et al. 2011b), Primulina Hance (Weber et al. 2011c), etc., and newly divided or restored genera, for example, Glabrella Mich. ...
... To better understand the generic placement of this species, molecular phylogenetic analysis was also performed. After consulting the relevant literature Li and Wang 2005;Wei et al. 2010;Wei 2018;Wen et al. 2019) and the molecular evidence, we concluded that this new species was assignable to a new genus, Actinostephanus gen. nov. ...
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Actinostephanus, a new genus from southern China, is described and colorfully illustrated with a single species, A. enpingensis. This new genus is morphologically most similar to Boeica and Leptoboea, nevertheless, it can be easily distinguished from the latter two by the following characteristics, such as leaves in whorls of three, all closely clustered at the top; corolla bowl-shaped, 5-lobed, actinomorphic; capsule hard, oblong-ovoid, short, 3-4 mm long, densely appressed villous, wrapped by persistent densely pubescent calyx lobes, style persistent. The new genus and related genera were sequenced using the next-generation sequencing technique. The whole plastid genome of the new genus is 154, 315-154, 344 bp in length. We reconstructed phylogenetic trees using the dataset of 80 encoded protein genes of the whole plastid genome from 47 accessions based on ML and BI analyses. The result revealed that the new genus was recovering in a polytomy including Boeica, A peer-reviewed open-access journal Fang Wen et al. / PhytoKeys 193: 89-106 (2022) 90 Rhynchotechum, and Leptoboea with strong support, congruent to the morphological evidence. A global conservation assessment was also performed and classifies A. enpingensis as Least Concern (LC). In addition, after a review of recently described species of Gesneriaceae, we propose that plant enthusiasts, especially Gesneriad fans, have been playing an increasingly important role in the process of new taxa-discoveries.
... Wei, F.Wen & M.Möller. It was confirmed and published using classical taxonomy, palynology, and phylogenetic analysis (Wei et al. 2010). Since then, some redefined genera, such as Hemiboea Clarke (Weber et al. 2011a), Loxostigma Clarke (Möller et al. 2014), Oreocharis , Paraboea (Clarke) Ridley (Puglisi et al. 2011), Petrocodon Hance (Weber et al. 2011b), Primulina Hance (Weber et al. 2011c), etc., and newly divided or restored genera, for example, Glabrella Mich. ...
... To better understand the generic placement of this species, molecular phylogenetic analysis was also performed. After consulting the relevant literature Li and Wang 2005;Wei et al. 2010;Wei 2018;Wen et al. 2019) and the molecular evidence, we concluded that this new species was assignable to a new genus, Actinostephanus gen. nov. ...
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Actinostephanus , a new genus from southern China, is described and colorfully illustrated with a single species, A. enpingensis . This new genus is morphologically most similar to Boeica and Leptoboea , nevertheless, it can be easily distinguished from the latter two by the following characteristics, such as leaves in whorls of three, all closely clustered at the top; corolla bowl-shaped, 5-lobed, actinomorphic; capsule hard, oblong-ovoid, short, 3–4 mm long, densely appressed villous, wrapped by persistent densely pubescent calyx lobes, style persistent. The new genus and related genera were sequenced using the next-generation sequencing technique. The whole plastid genome of the new genus is 154, 315 - 154, 344 bp in length. We reconstructed phylogenetic trees using the dataset of 80 encoded protein genes of the whole plastid genome from 47 accessions based on ML and BI analyses. The result revealed that the new genus was recovering in a polytomy including Boeica , Rhynchotechum , and Leptoboea with strong support, congruent to the morphological evidence. A global conservation assessment was also performed and classifies A. enpingensis as Least Concern (LC). In addition, after a review of recently described species of Gesneriaceae, we propose that plant enthusiasts, especially Gesneriad fans, have been playing an increasingly important role in the process of new taxa-discoveries.
... The combination of molecular and morphological data, consistent with the geographical distribution, confirms that this is a new species and genus. This methodology has been shown to be particularly efficient in the circumscription of genera and species, including the discovery of a considerable number of new genera in the Gesneriaceae (e.g., Araújo et al. 2010;Clark et al. 2010;Wei et al. 2010;Middleton & Möller 2012). ...
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A new genus of Gesneriaceae, Bopopia Munzinger & J.R.Morel gen. nov., is described from New Caledonia. The genus is based on B. parviflora Munzinger & J.R.Morel gen. et sp. nov., a new species collected during an expedition on Mt Katalupaik, in the North Province of New Caledonia’s main island. Originally considered as a species of Coronanthera, our phylogenetic analysis – including 19 species within Coronanthereae and two individuals of B. parviflora gen. et sp. nov., and using three molecular markers (nuclear rDNA ITS, and chloroplast regions trnL-trnF and trnE-trnT) – showed that the new species is not close to Coronanthera in subtribe Coronantherinae, but belongs to subtribe Negriinae where it is sister to Depanthus. From that genus Bopopia gen. nov. differs in floral symmetry (zygomorphic vs actinomorphic) and the number of stamens (4 vs 5). From the other genera of Negriinae the new genus differs in the white corolla and its indeterminate thyrse with 3 to 5 levels of branching. The morphological circumscription of the subtribe Negriinae is amended to include Bopopia gen. nov. Two keys are provided, one to the subtribes in the tribe Coronanthereae, and one to the genera in subtribe Negriinae. Following the IUCN Red List categories and criteria, the conservation status of B. parviflora gen. et sp. nov. is provisionally assessed as Endangered (EN).
... During an expedition in September 2016 investigating the karst flora of Guizhou, we collected a special Petrocodon species in flower from a single locality in Tongzi County, Guizhou, China. The species has four fertile stamens, clearly differentiating it from all described species of Petrocodon except P. hunanensis (Wang et al. 1990, 1998, Wei et al. 2010a, 2010b, Jiang et al. 2011, Liu et al. 2011, Weber et al. 2011, Wen et al. 2012, Hong et al. 2014, Chen et al. 2014, Xu et al. 2014, Li and Wang 2015, Yu et al. 2015, Guo et al. 2016, Cen et al. 2017, Lu et al. 2017. To further investigate the status of this special species and the phylogenetic relevance of the four fertile stamens, we undertook a careful comparison and employed molecular markers to reconstruct the phylogeny of the genus. ...
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Petrocodon tongziensis R.B.Zhang & F.Wen, a new species from northern Guizhou province, China, is described and illustrated based on molecular and morphological evidence. The new species was found growing in crevices and on tufa of moist surfaces of limestone hills in Tongzi County. A maximum parsimony (MP) analysis based on the combined ITS and trnL‐F DNA regions showed that the new species falls within a large polytomy within Petrocodon, but is resolved as most closely related to an unidentified species (WF2014) and these two taxa are in turn resolved as sister to Petrocodon hunanensis X.L.Yu & Ming Li. This is congruent with the fact that both P. hunanensis and P. tongziensis have four fertile stamens, a character state likely to be an ancestral state distinguishing this clade from the rest of Petrocodon. Petrocodon tongziensis differs from P. hunanensis by lacking a terrestrial stem, as well as by the number of bracts, presence of bracteoles, shape of the lobes of the upper lip, and reduced number and length of staminodes.
... Generic delimitation in Asian Gesneriaceae has been the focus of much recent research and has led to considerable change (Wei et al., 2010;Möller et al., 2011Möller et al., , 2014Möller et al., , 2016Puglisi et al., 2011Puglisi et al., , 2016Wang et al., 2011;Weber et al., 2011aWeber et al., , 2011bMiddleton & Möller, 2012;Middleton et al., 2014. This research, much of it based on the results of DNA sequence data, has resulted in an overall reduction in the number of genera but also the description of new genera to accommodate new species which were found to belong to previously unknown lineages , and the splitting up of genera found to be polyphyletic (Weber et al. 2011a;Möller et al., 2014). ...
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Litostigma is a recently described small genus with two species confined to limestone karsts in southwestern China and adjacent Vietnam. During the course of field works on the limestone karsts of the China–Vietnam border area, two unknown species of Litostigma were collected. Molecular phylogenetic analyses based on nuclear ITS sequences strongly confirm the placements of the two new species in Litostigma. However, these two new species can be distinguished from the previously known species by distinct morphological characters. Thus, Litostigma pingbianense and L. napoense are recognized as two new species. This adds to the morphological variability of the genus. Most importantly, both simple and divided stigmas does occur in this genus.
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Based on an updated taxonomy of Gesneriaceae, the biogeography and evolution of the Asian Gesneriaceae are outlined and discussed. Most of the Asian Gesneriaceae belongs to Didymocarpoideae, except Titanotrichum was recently moved into Gesnerioideae. Most basal taxa of the Asian Gesneriaceae are found in the Indian subcontinent and Indo-China Peninsula, suggesting Didymocarpoideae might originate in these regions. Four species diversification centers were recognized, i.e. Sino-Vietnam regions, Malay Peninsula, North Borneo and Northwest Yunnan (Hengduan Mountains). The first three regions are dominated by limestone landscapes, while the Northwest Yunnan is well-known for its numerous deep gorges and high mountains. The places with at least 25% species are neoendemics (newly evolved and narrowly endemic) which were determined as evolutionary hotspots, including Hengduan Mountains, boundary areas of Yunnan-Guizhou-Guangxi in Southwest China, North Borneo, Pahang and Terengganu in Malay Peninsula, and mountainous areas in North Thailand, North Sulawesi Island. Finally, the underlying mechanisms for biogeographical patterns and species diversification of the Asian Gesneriaceae are discussed.
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available online: http://www.iapt-taxon.org/historic/2006.htm
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We have analysed and characterised the phylogenetic potential of a nuclear developmental gene, cycloidea (originally isolated from Antirrhinum), involved in the development of floral zygomorphy. We have compared the evolution of part of this putative single copy gene in Old World Gesneriaceae with two contrasting DNA sequence regions, using two sets of data (a 'genus' data set and a 'species' data set); the chloroplast trnL(UAA) intron and the spacer between the trnL (UAA) 3' exon and trnF (GAA) were relatively conserved and suitable for phylogenetic reconstruction at genus level. The multicopy internal transcribed spacers (ITS1 and ITS2) of nuclear ribosomal DNA in contrast appear to be evolving about five times faster and are suitable for resolution at the species level. The putative homologue of cycloidea (Gcyc) has an intermediate substitution rate about three times faster than the chloroplast intron/spacer region. However, the level of pairwise sequence divergence of Gcyc is higher than that of ITS at very low levels of divergence. This difference in apparent rate of molecular evolution between ITS and Gcyc at different levels of the taxonomic hierarchy we attribute to the process of molecular drive in the multicopy ITS. At lower levels of divergence (e.g. between closely related species) fixation of genetic changes in the multicopy ribosomal DNA acts as a restraint on evolutionary rate, whereas third codon position changes in coding single copy nuclear (scnDNA) genes are unconstrained. However, at high levels of divergence (e.g. between general, scnDNA evolution is more functionally constrained than that of ITS and Gcyc therefore Varies less. The small restraining effect of concerted evolution is not noticeable at these levels of sequence divergence. All three regions appear to evolve in a clock-like manner and are found to be suitable for phylogenetic reconstruction by parsimony, resulting in the same or similar topologies. We have examined the Gcyc sequences of three species that have reverted to actinomorphy from a zygomorphic condition. The gene appears to be intact and therefore, by implication, functional in these species. Furthermore, in one of these clades there has been a reversion back to zygomorphy which also implies that the gene is intact. We therefore suggest that in naturally occurring actinomorphic Gesneriaceae Gcyc continues to have a functional role, but zygomorphy is reduced by modifying genes. There is no convincing evidence that Gcyc evolves faster in actinomorphic lineages.
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The 'didymocarpoid Gesneriaceae' (traditional subfam. Cyrtandroideae excluding Epithemateae) are the largest group of Old World Gesneriaceae, comprising 85 genera and 1800 species. We attempt to resolve their hitherto poorly understood generic relationships using three molecular markers on 145 species, of which 128 belong to didymocarpoid Gesneriaceae. Our analyses demonstrate that consistent topological relationships can be retrieved from data sets with missing data using subsamples and different combinations of gene sequences. We show that all available classifications in Old World Gesneriaceae are artificial and do not reflect natural relationships. At the base of the didymocarpoids are grades of clades comprising isolated genera and small groups from Asia and Europe. These are followed by a clade comprising the African and Madagascan genera. The remaining clades represent the advanced Asiatic and Malesian genera. They include a major group with mostly twisted capsules. The much larger group of remaining genera comprises exclusively genera with straight capsules and the huge genus Cyrtandra with indehiscent fruits. Several genera such as Briggsia, Henckelia, and Chirita are not monophyletic; Chirita is even distributed throughout five clades. This degree of incongruence between molecular phylogenies, traditional classifications, and generic delimitations indicates the problems with classifications based on, sometimes a single, morphological characters.
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 Aeschynanthus Jack, an epiphytic genus with c.160 species, is widespread in SE Asia. We selected 50 species for ITS nrDNA sequencing, to include all biogeographic areas and all infrageneric groupings, which are currently based on seed morphology. Some species were sequenced directly from PCR product; others cloned because of ITS length polymorphisms. The clone sequences were analysed individually and combined in an elision matrix. Results extend earlier findings that Aeschynanthus is divided into two clades, one occurring primarily in mainland SE Asia and the other in Malesia. This pattern is interpreted as indicating an ancient vicariance event followed by dispersal and plate fusion. Clade I has straight or clockwise spiral orientation of the testa cells and clade II anticlockwise spiral orientation. In clade I some species of section Microtrichium form a basal group with other sections being polyphyletic or paraphyletic. In clade II the monophyletic section Aeschynanthus is nested within the paraphyletic basal Microtrichium.
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Thesis (Ph. D.)--North Carolina State University. Includes bibliographical references (leaves 262-266). Includes vita. microfiches. s
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Streptocarpus shows great variation in vegetative architecture. In some species a normal shoot apical meristem never forms and the entire vegetative plant body may consist of a single giant cotyledon, which may measure up to 0.75 m (the unifoliate type) or with further leaves arising from this structure (the rosulate type). A molecular phylogeny of 87 taxa (77 Streptocarpus species, seven related species, and three outgroup species) using the internal transcribed spacers and 5.8S region of nuclear ribosomal DNA suggests that Streptocarpus can be divided into two major clades. One of these broadly corresponds to the caulescent group (with conventional shoot architecture) classified as subgenus Streptocarpella, whereas the other is mainly composed of acaulescent species with unusual architecture (subgenus Streptocarpus). Some caulescent species (such as S. papangae) are anomalously placed with the acaulescent clade. Available cytological data are, however, completely congruent with the two major clades: the caulescent clade is x = 15 and the acaulescent clade (including the caulescent S. papangae) is x = 16 (or polyploid multiples of 16). The genera Linnaeopsis, Saintpaulia, and Schizoboea are nested within Streptocarpus. The sequenced region has evolved, on average, 2.44 times faster in the caulescent clade than in the acaulescent clade and this is associated with the more rapid life cycle of the caulescents. Morphological variation in plant architecture within the acaulescent clade is homoplastic and does not appear to have arisen by unique abrupt changes. Instead, rosulate and unifoliate growth forms have evolved several times, reversals have occurred, and intermediate architectures are found. An underlying developmental plasticity seems to be a characteristic of the acaulescent clade and is reflected in a great lability of form.