Begonia medogensis, a new species of Begoniaceae from Western China and Northern Myanmar Author Li, Jian-Wu Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, P. R. China Author Tan, Yun-Hong https://orcid.org/0000-0001-6238-2743 Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, P. R. China & South Asia Biodiversity Research Institute, Chinese Academy of Sciences, Yezin, Nay Pyi Taw 05282, Myanmar Author Wang, Xi-Long Tibet Plateau Institute of Biology, Lhasa 850001, P. R. China Author Wang, Cheng-Wang School of Life Sciences, Nanchang University, Nanchang 330031, Jiangxi, P. R. China Author Jin, Xiao-Hua Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P. R. China xiaohuajin@ibcas.ac.cn text PhytoKeys 2018 2018-07-02 103 13 18 http://dx.doi.org/10.3897/phytokeys.103.25392 journal article http://dx.doi.org/10.3897/phytokeys.103.25392 1314-2003-103-13 FFEABA43E33EFFCAFFD0FFC130421130 1308282 Begonia medogensis JianW.Li, Y.H.Tan & X.H.Jin sp. nov. Figure 1 Diagnosis. Begonia medogensis is morphologically similar to B. goniotis , B. griffithiana , B. nepalensis and B. sandalifolia , but can be easily distinguished from them by having leaves ovate-lanceolate, 6.0-8.0 x 1.5-2.5 mm, base slightly asymmetric, margins remotely and irregularly denticulate; triangular to lanceolate stipules; staminate flowers with outer 2 segments broadly ovate, inner 2 spathulate; pistillate flowers with perianth segments unequal, outer 4 larger, broadly ovate, inner 1 smallest, spathulate; cylindroid ovary, larger wing oblong, apex truncate. Type . CHINA . Tibet , Medog County , Beibeng town , semi-evergreen forest in a subtropical area, 29°15'09"N , 95°13'31"E . 1381 m a.s.l. , 16 November 2017 , flowering, Xiaohua Jin , Jianwu Li , Xilong Wang & Chengwang Wang 19331 ( holotype : HITBC!, isotype: HITBC!, PE!, K!) Figure 1. Begonia medogensis JianW.Li, Y.H.Tan & X.H.Jin. (photographed by Jian-Wu Li). A Habitat B-E Flowers F Pedicel and ovary (showing large wing) G Male flowers (face view) H Ovary (showing loculus) I Flowers J Dissection of female flower K Dissection of male flower L Leaves M Anther with filament (under dissection mirror, bar = 1 mm ) N Female flower (face view). Description. Perennial herbs, caulescent, erect. Rhizomes short, stout. Stems reddish-purple, densely pubescent, 0.3-1.0 m tall, with internode 6-15 cm long, upper part well-branched, with internode 2-5 cm long. Leaves cauline; stipules persistent, triangular to lanceolate, 6.0-8.0 x 1.5-2.5 mm, apex acuminate to cuspidate; petiole 1.2-2.7 cm long, densely pubescent; leaf blade ovate-lanceolate, slightly asymmetric, 6.0-10.0 x 2.0-3.7 cm, adaxially green, slightly hairy, abaxially greenish-white, hairy on venation, venation palmate-pinnate, 5-8-veined, base slightly oblique, rounded to subcordate, margins remotely and irregularly denticulate, apex caudate-acuminate. Inflorescences terminal and axillary, sub-corymb, monoecious, to 6 cm, sub-pendulous, peduncles 2.7-4.0 cm long, secondary 0.5-1.0 cm long, terminally with 1-5 flowers; floral bracts lanceolate to ovate-lanceolate, 5.0-10.0 x 1.7-5.0 mm, thickly papery, glabrous, apex acuminate. Staminate flowers: pedicel 10-15 mm long; tepals 4, white, outer 2 broadly ovate, 15-17 x 12-14 mm, tinted with pink, glabrous, apex rounded; inner 2 spathulate, 11-14 x 6-8 mm, glabrous, apex obtuse to rounded; stamens 60-80; filaments free, 0.5-1.2 mm long, sub-equal, fused at base into a column; anthers broadly lorate, 0.8-1.1 mm long, apex emarginate. Pistillate flowers: pedicel 11-20 mm long, tepals 5, white, unequal, glabrous, outer 4 broadly ovate, the outmost 2 tinted with pink, 12-14 x 9-12 mm, apex rounded, other 2 slightly larger, 13-15 x 10-12 mm, apex obtuse to rounded; the inner 1 smallest, spathulate, 8-10 x 7-9 mm, apex rounded; ovary glabrous, 2-loculed; placentae axile, bilamellate; styles 2, fused at base; stigmas 2-cleft, spiralled. Capsule sub-pendulous, cylindroid, 5.0-8.0 x 1.5-2.5 mm; wings 3, adaxial 1 larger, oblong, 7-9 mm broad, apex truncate, lateral 2 less developed, 2-3 mm broad. Phenology. Flowering from October to December. Distribution and habitat. This new species grows in subtropical areas in Beibeng town, Medog County, Tibet, China, at an elevation of 700-1400 m and in Putao district, Kachin state, Myanmar, at an elevation of 600-1200 m. Etymology. The species is named after the holotype locality, Medog County, in Tibet, China. Additional specimens examined ( paratype ). MYANMAR . Putao district , Kachin state , in tropical montane forest, 27°37'15"N , 97°53'14"E . 900 m a.s.l. , 1 December 2016 , flowering, Myanmar Exped. M 0727 (HITBC!) . Note. Morphologically, the new species is similar to B. goniotis , B. griffithiana , B. nepalensis and B. sandalifolia , but differs from them by the shape of stipules and leaves, base and margins of leaves, both male and female flowers having unequal perianth segments, cylindroid ovary etc. (see Table 1 ). Table 1. Differences between Begonia medogensis , B. goniotis , B. griffithiana , B. nepalensis and B. sandalifolia .

Character	B. medogensis	B. goniotis	B. griffithiana	B. nepalensis	B. sandalifolia
Stem	internode 6-15 cm long	internode 4-10 cm long	internode 3-9 cm long	internode 4-11 cm long	internode 9-20 cm long
Stipules	persistent, triangular to lanceolate, 6.0-8.0 x 1.5-2.5 mm	persistent, ovate, 6-13 x 4-10 mm	persistent, lanceolate, 4-13 x 1-2 mm	deciduous, lanceolate	persistent, oblong, 6-10 x 2-4 mm
Leaves	petiole 1.2-1.7 cm long, ovate-lanceolate, base slightly asymmetric, 6.0-10.0 x 2.0-3.7 cm, margins remotely and irregularly denticulate, apex caudate-acuminate	petiole 1.0-4.6 cm long, lanceolate, base strongly asymmetric, 10-15 x 0.6-2.5 cm, margins entire or serrate near apex, apex long acuminate	petiole 0.2-1 cm long, oblong-lanceolate to lanceolate, base strongly asymmetric, 5-18 x 2-5 cm, margins serrulate or with small teeth at ends of the main veins, apex acuminate	petiole 1-3 cm long, ovate-lanceolate, base strongly asymmetric, 15-17 x 4-11 cm, margins shallowly dentate, apex caudate-acuminate	petiole 0.7-1.3 cm long, ovate to oblong, base strongly asymmetric, 10-15 x 3-5 cm, margins entire or serrate, apex acuminate
Male flower	tepals 4, outer 2 broadly ovate, 15-17 x 12-14 mm, tinted with pink, inner 2 spathulate, 11-14 x 6-8 mm, white, stamens 60-80, anthers broadly lorate	not seen	tepals 4, outer 2 orbicular to oblong, 4-14 x 2-11 mm, pale pink to white, inner 2 lanceolate to linear, 3-9 x 1-4 mm, pale pink, stamens 20-30, anthers elliptic-globose	tepals 2, ovate, 7-10 x 7-9 mm, pale pink to white, stamens 20-40, anthers elliptic globose	tepals 4, outer 2 round, 18 x 18 mm, inner 2 oblong, stamens ca. 50, anthers obovoid
Female flower	tepals 5, unequal, outer 4 broadly ovate, the outmost 2 tinted with pink, 12-14 x 9-12 mm, other 2 slightly larger, 13-15 x 10-12 mm; the inner 1 smallest, spathulate, 8-10 x 7-9 mm	not seen	tepals 5-6, equal, 3-4 larger and 1-2 smaller, oblong elliptic to obovate orbicular, outer tepals 6-11 x 5-7 mm, pale pink to white, inner tepals smaller	tepals 4-5, equal, outer tepals 10-15 x 7-10 mm, pale pink to white, inner tepals smaller	not seen
Ovary	cylindroid, 5-8 x 1.5-2.5 mm, larger wing oblong, 7-9 mm broad, apex truncate	ellipsoid, 10-13 x 6 mm, larger wing oblong, 10-16 mm broad, apex rounded	oblong-ellipsoid, 5-7 x 2-3 mm, larger wing triangular, 12-18 mm broad, apex obtuse	narrowly ellipsoid, 12-15 x 5 mm, larger wing oblong, 15-23 mm broad, apex truncate	ellipsoid, 13-16 x 6 mm, larger wing oblong, 13-16 mm broad, apex rounded