The genus Begonia (Begoniaceae) is the sixth largest genus of flowering plants, comprises 1930 species and is distributed in the tropical and subtropical areas in the world. In China, about 204 species have been recorded.
In a field survey of the Puer area in Yunnan province (China), researchers from Xisuangbanna Tropical Botanical Garden (XTBG) collected an unknown Begonia species. After examining the type specimens and literature of Begonia from China and the adjacent regions, the authors identified it as a new species.
The researchers named the new species as Begonia austroyunnanensis to refer to the type locality in southern Yunnan and got it published in journal Taiwania.
Begonia austroyunnanensis is similar to B. subhowii in having short erect stems, obliquely ovate leaves, and white flowers, but can be distinguished by its stem, petioles, and peduncle having conspicuous, red, linear dots and the much longer abaxial wing of the capsule.
Begonia austroyunnanensis is endemic to Menglian county, Puer, Yunnan province. It grows on shaded rocky limestone slopes in broadleaved forest near village at an elevation of 920 m, flowering from December to January and fruiting from January to February.
Begonia austroyunnanensis is geographically limited to the type location with less than 100 mature individuals growing on the limestone hills surrounded by croplands and the natural habitat has been severely disturbed by human activities.
Based on the current data with a narrow distribution range, and the population possibly continuing decline due to habitat disturbance, the researchers considered that the new species be critically endangered according to the IUCN Red List Categories and Criteria.
Department of Gardening and Horticulture, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan 666303, China