Tuesday, September 6, 2022

[Botany • 2021] Begonia catbensis (Begoniaceae, section Coelocentrum) • A New Species from northern Vietnam


Begonia catbensis  L.N.Dong, K.S.Nguyen & Y.M.Shui,

in Dong, Nguyen, Shui, ... et Nguyen, 2021. 

Abstract
Begonia catbensis, a new species in Begonia sect. Coelocentrum is described and illustrated. The new species was discovered in lowland limestone hills at Cat Ba National Park and can be easily distinguished from all its congeners by having dendritic hairs on the petiole, adaxial veins and stipules, fimbriate bracts and bracteoles, dense conical bullae on the upper surface of the leaf blade, two tepals in the pistillate flowers and a glabrescent ovary with verrucose wings. Based on IUCN Criteria, the species is currently assessed as “Endangered” (D).

Keywords: Begonia, Cat Ba, endangered plant, new species, Vietnam

Begonia catbensis  L.N.Dong, K.S.Nguyen & Y.M.Shui,
A plants growing on rocks in the wild B habit C apical shoot bearing stipules D young leaf, abaxial view E part of adaxial leaf surface showing bullae, setae and palmate veins F dendritic hairs on petiole and abaxial veins G portion of leaf showing reddish setae on bullae and along margin.
Photos and layout by K.S. Nguyen & L.N. Dong.


Begonia catbensis  L.N.Dong, K.S.Nguyen & Y.M.Shui,
A apical part of inflorescence showing peduncle, pedicel, bracts, bracteoles, staminate and pistillate flowers B staminate and pistillate flowers C staminate flower (upper) in front view D stamens E pistillate flower-top view F pistillate flower, lateral view G dissected styles and stigmas H fruits and their cross-cut.
Photos and layout by K.S. Nguyen & L.N. Dong.

Begonia catbensis L.N.Dong, K.S.Nguyen & Y.M.Shui, sp. nov.
 
Diagnosis: Morphologically similar to several Begonia having conically bullate leaves and others with a rugulose leaf surface with white maculation and a ciliolate tepal margin, but can be easily distinguished from them by the dendritic hairs on the petioles, abaxial veins and the keeled mid-rib of the stipules, glabrous peduncles, pistillate flowers with 2 tepals and glabrescent ovaries with verrucose wings.


 Li-Na Dong, Khang Sinh Nguyen, Yu-Min Shui, Hieu Quang Nguyen, Wei‑Bin Xu and Xuan Khu Nguyen. 2021. Begonia catbensis (sect. Coelocentrum, Begoniaceae), A New Species from northern Vietnam. PhytoKeys. 179: 1-12. DOI: 10.3897/phytokeys.179.65812