Begonia laotica Y.H.Tan & H.B. Ding (2020: 188)

Bon, Trinh Ngoc, Do, Thi Thanh Ha, Le, Thi Hanh, Lo, Minh Duc, Zimmer, Heidi & Lin, Che- Wei, 2023, Begonia saxifragoides sp. nov. and two new records of Begonia (Begoniaceae) from northern Vietnam, Phytotaxa 600 (1), pp. 16-24 : 23

Begonia laotica Y.H.Tan & H.B. Ding (2020: 188) .

Type:— LAOS. Oudomxay Province: Maung Xai, Phou Hin Phee National Biodiversity Conservation Area, 102°08’47.97”E, 20°43’18.69”N. 1,378 m elev., 25 October 2018, flowering, Y. H. Tan & H. B. Ding L0827 (holotype HITBC; isotype HNL) .

Distribution and ecology:— Begonia laotica was described in 2020 and reported as endemic to Phou Hin Phee National Biodiversity Conservation Area in northern Laos. Here we report it for the first time from Ngoc Chien Commune, Muong La District, Son La Province: across from the northeast border with Laos. It is restricted to limestone karst mountains at 1,280 m elevation in the lower half of shaded vertical cliffs in montane moist forest. Begonia laotica shows a small range of variation in vestiture of leaves between different populations and individuals. For example, Laos populations have completely glabrous upper leaf surfaces, whereas, in Vietnam, some individuals are sparsely puberulous.

Specimen examined:— VIETNAM. Son La Province: Muong La District, Ngoc Chien Commune , 1,280 m elevation, 22 August 2022, Trinh Ngoc Bon, Thi Thanh Ha Do, Thi Hanh Le, Minh Duc Lo, Heidi Zimmer, Lo Van Chieu, Sung A Giang & Sung A Chu SCU2022-03 ( VAFS) .