Saturday, May 29, 2021

[Botany • 2021] Taxonomic Studies on Begonia (Begoniaceae) in Myanmar II: Seven New Species from Myanmar


Begonia amnicola Y.H.Tan, M.B.Maw & H.B.Ding

in Maw, Ding, Yang, Win et Tan, 2021.

Abstract
This paper presents the result of consecutive floristic survey in Myanmar. Seven new species of Begonia (Begoniaceae), B. casseabri Y.H.Tan, M.B.Maw & H.B.Ding, B. persistens Y.H.Tan, M.B.Maw & H.B.Ding, B. latibracteata Y.H.Tan, M.B.Maw & H.B.Ding from Putao District, Kachin State, B. natmataungensis Y.H.Tan, M.B.Maw & H.B.Ding from Natma Taung National Park, Chin State, B. amnicola Y.H.Tan, M.B.Maw & H.B.Ding, B. sagaingensis Y.H.Tan, M.B.Maw & H.B.Ding and B. chindwinensis Y.H.Tan, M.B.Maw & H.B.Ding from Htamanthi Wildlife Sanctuary, Sagaing Region, are described and illustrated. All of the new species belongs to Begonia section Platycentrum (Klotzsch) A.DC. Detailed descriptions, colored photographs, habitat and distribution data for the seven new species are provided. A diagnostic key to species of Begonia sect. Platycentrum in Myanmar is presented.

Keyword: Begonia Sect. Platycentrum, biodiversity, Myanmar (Burma), bracteole, CAS-SEABRI


     


  Begonia casseabri Y.H.Tan, M.B.Maw & H.B.Ding, sp. nov. 
Begonia Sect. Platycentrum (Klotzsch) A.DC. 

Diagnosis: Begonia casseabri is morphologically similar to B. dicressine Wahlsteen (2019: 242) from Northern Myanmar under the section Platycentrum. But it can be distinguished from the similar species by lacerate bracteoles under the ovary (vs. without) and tomentose capsule (vs. glabrous). 

Distribution: This species is known only from the type locality, Putao District, Kachin State, Northern Myanmar (Fig. 8). 

Ecology: Growing on the granite rocks of tropical montane forest at about 6001200 m altitude. 


Etymology: The species epithet is derived from the abbreviation of Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences (CAS-SEABRI); noun in apposition. 
Vernacular: ြမဧကရီေǤကပန်း (mya ekare kywawy paann). 


Begonia persistens Y.H.Tan, M.B.Maw & H.B.Ding, sp. nov. 
 Begonia Sect. Platycentrum (Klotzsch) A.DC. 


 Diagnosis: Begonia persistens is morphologically similar to B. rheophytica M.Hughes (in Hughes et al. 2019: 286, Maw et al. 2020) from Northern Myanmar in having symmetric leaves with grooved petiole and with 2 bracteoles under the ovary but it can be distinguished by the following distinct characters including leaf blade broadly oval to ovate, 14–22 × 9–10 cm (vs. narrowly lanceolate, 13.3–18.2 × 2.2–4.0 cm), larger bracteoles under the ovary, 0.8–1.8 × 1–1.4 cm (vs. 0.6−0.8 × 0.3−0.5 cm) and white pilose stipule (vs. glabrous).

Distribution: The species can be found only in the type locality, Putao District, Kachin State, Northern Myanmar (Fig. 8). 

Ecology: Growing on the large rock under light to medium shade of lowland forest at about 500700 m altitude. 

Etymology: The species epithet ‘persistens’ refers to its persistent bracteoles under the ovary. 
Vernacular: ပွငခ့် ရံ ွကတ် ညေ် Ǥကပနး် (pwint hkan rwat tai kywawy paann).



Begonia latibracteata Y.H.Tan, M.B.Maw & H.B.Ding, sp. nov. 
 A. habitat; B. petiole, showing whitish linear dots; C. rhizomes; D. male flowers (front view); E. male flowers (back view); F. female flower (front view); G. female flower (side view, showing bracteoles under the ovary by arrows); H. inflorescence; I. stigma (side view); J. stipule (front and back view); K. ovary, showing reddish succulent strigose; L. tepals of male flower, androecium with pedicel; M. tepals of female flower, gynoecium and ovary with pedicel; N. serial cross section of ovary; O. capsule with unequal wings.
(photographed by Y.H. Tan).

Begonia latibracteata Y.H.Tan, M.B.Maw & H.B.Ding, sp. nov. 
Begonia Sect. Platycentrum (Klotzsch) A.DC.  

Diagnosis: Begonia latibracteata is morphologically similar to B. pedatifida H.Lév. (in Léveillé 1909: 21) in having similar lacerate leaves under the section Platycentrum. But it can be distinguished from the similar species by the following characters: white linear papillae and rusty tomentum on petiole and peduncle (vs. densely or sparsely villous), larger stipules (1.8-3 × 1–1.7 cm vs. ca. 1 × 0.8 cm), with 2 bracteoles under the ovary (vs. without), ovary with densely reddish succulent strigose hairs (vs. glabrous or pilose).

Distribution: This species known only from the type locality, Putao District, Kachin State, Northern Myanmar (Fig. 8). 

Ecology: Growing on rocky slopes in shaded moist environment of tropical montane forest at about 1000 m altitude. 

Etymology: The species epithet refers to its ovate bracteoles under the ovary. 
Vernacular: ပွငခ့် ရံ ွကƳ်ကးီေǤကပနး် (pwint hkan rwat kyee kywawy paann).


Begonia natmataungensis Y.H.Tan, M.B.Maw & H.B.Ding, sp. nov. 
 A. habitat; B. rhizomes; C. male flowers (frond and side view); D. male flower (back view); E. female flower (back view); F. bulbils; G. petiole, showing reddish linear dots; H. single leaf (front and back view); I. inflorescence; J. fruits with unequal wings; K. tepals of male flower, androecium, pedicel; L. tepals of female flower, gynoecium, ovary with pedicel; M. serial cross section of ovary; N. capsule.
(photographed by H.B. Ding and Y.H. Tan).

Begonia natmataungensis Y.H.Tan, M.B.Maw & H.B.Ding, sp. nov. 
Begonia Sect. Platycentrum (Klotzsch) A.DC.  

Diagnosis: Begonia natmataungensis shares similar morphological characters to B. koelzii R.Camfield (in Camfield and Hughes 2018: 51) in having lacerate leaves with bulbils. But it can be easily distinguished from the similar species by lamina lobes, shallowly incised, divided to 1/31/2 of leaf length (vs. deeply incised, divided to 2/3 of leaf length), without bracteoles (vs. with 2 small bracteoles under the female flower) and styles 2 (vs.3).

Distribution: This species is known only from the type locality, Natma Taung National Park, Chin State, Myanmar (Fig. 8). 

Ecology: Growing on rocky cliffs of evergreen forest at about 1500–3100 m altitude. 

Etymology: The species epithet refers to its type locality, Natma Taung National Park, Chin State, Myanmar. 
Vernacular: ေခȆdzǾးစǽမ်ေǤကပန်း (khaw nu m'cong kywawy paann). 




Begonia amnicola Y.H.Tan, M.B.Maw & H.B.Ding, sp. nov.
 A. habitat; B. rhizomes; C. flowers; D. flowers (close-up view); EF. flowers (side view); G. single leaf (front and back view); H. leaf (abaxial), showing red hispid on veins; I. leaf (adaxial), showing remotely serrate margin with reddish hispid; J. stipules; K. capsule with unequal wings; L. androecium (back view); M. bracts; N. inflorescence; O. tepals of male flowers, androecium, pedicel; P. tepals of female flower, gynoecium, ovary with pedicel; Q. serial cross section of ovary (close-up view); R. serial cross section of ovaries.
 (photographed by H.B. Ding).

Begonia amnicola Y.H.Tan, M.B.Maw & H.B.Ding, sp. nov. 
Begonia Sect. Platycentrum (Klotzsch) A.DC.  

Diagnosis: Begonia amnicola is mostly similar to Begonia pellionioides Y.M.Shui & W.H.Chen (in Wang et al. 2015: 564) from China (Yunnan) in having erect stem, cauline leaves and elliptic-lanceolate to lanceolate leaves but it can be easily distinguished by the following characters including 2-locular ovary (vs. 3-locular ovary), styles 2 (vs. 3) and unequal wings (vs. equal or slightly unequal wings).


Distribution: This species is known only from the type locality, Htamanthi Wildlife Sanctuary, Hkamti District, Sagaing Region, Northern Myanmar (Fig. 8).

 Ecology: It grows on moist soil nearby or in stream at about 100-200 m altitude. 

Etymology: The specific epithet refers to the habitat in which this species occurs. 
Vernacular: ƭကယစ် ငေ် Ǥကပန်း (kyal sin kywawy paann).



Begonia sagaingensis Y.H.Tan, M.B.Maw & H.B.Ding, sp. nov. 
Begonia Sect. Platycentrum (Klotzsch) A.DC.  

Diagnosis: Begonia sagaingensis is morphologically similar to Begonia menglianensis Y.Y. Qian (2001: 461) from China (Yunnan) in its rhizomatous habit and broadly ovate leaf with densely villous petiole. But it can be easily distinguished by white to pinkish-white flower (vs. pinkish), overlapping leaf base (vs. without overlapping), serrate apex of female flower tepals (vs. entire) and free filaments (vs. fused at base). 

Distribution: The species is only known from the type locality, Htamanthi Wildlife Sanctuary, Hkamti District, Sagaing Region, Northern Myanmar (Fig. 8). 

Ecology: The species was discovered on the moist soil slope of deep shaded environment of tropical hill forest. 

Etymology: The species epithet ‘sagaingensis’ refers to its type locality, Sagaing Region, Myanmar. 
Vernacular: စစက် င း်ေǤကပန်း (sagaing kywawy paann)

Begonia chindwinensis Y.H.Tan, M.B.Maw & H.B.Ding, sp. nov. 
 A. habitat; B. male flowers (front view); C. male flower (back view); D. female flower (front view); E. inflorescence; F. tepals of male flower, androecium, pedicel; G. stipules; H-I. bracts; J. capsule; K. tepals of female flower, gynoecium, ovary with pedicel; L. cross section of ovary; M. single leaf (back view); N. single leaf (front view).
(photographed by H.B. Ding).

Begonia chindwinensis Y.H.Tan, M.B.Maw & H.B.Ding, sp. nov. 
Begonia Sect. Platycentrum (Klotzsch) A.DC.  

Diagnosis: The new species is similar to Begonia gulinqingensis S.H. Huang & Y.M. Shui (in Huang & Shui 1994: 334) from China (Yunnan) in the rhizomatous habit, thick texture of leaves and suborbicular shape of leaves, but differs in filaments free (vs. fused at base), styles 2 (vs. 3) and ovary 2-loculed (vs. 3-loculed).
 
Distribution: The new species is only found in the type locality, Htamanthi Wildlife Sanctuary, Hkamti District, Sagaing Region, Northern Myanmar (Fig. 8). 

Ecology: It grows in cool and moist environment in evergreen forest at about 185 m altitude. 

Etymology: The specific epithet refers to its type locality, Htamanthi Wildlife Sancturay is one of the key biodiversity area in Chindwin River Basin.
Vernacular: ချငး်တငွး်ေǤကပန်း (chindwin kywawy paann). 


Mya Bhone Maw, Hong-Bo Ding, Bin Yang, Pyae Pyae Win and Yun-Hong Tan. 2021. Taxonomic Studies on Begonia (Begoniaceae) in Myanmar II: Seven New Species from Myanmar. Taiwania. 66(2); 214-231. DOI: 10.6165/tai.2021.66.214