Abstract
The genus Ailanthus Desfontaines (1788: 265) of the family Simaroubaceae comprises 5–10 species distributed in South and Southeast Asia as well as northern Australia (Nooteboom 1962, Peng & Thomas 2008). The species can be classified into two groups, i.e., one with toothed leaflets and the other with entire-margined leaflets. The latter group currently includes five species, A. triphysa (Dennstedt 1818: 32) Alston (1931: 41), A. vietnamensis H.V.Sam & Nooteboom (2007: 555), A. fordii Nooteboom (1962: 220), A. integrifolia Lamarck (1792: 417), and A. guangxiensis S.L.Mo ex C.F.Liang & S.L.Mo (1982: 145). The last species was described based on two fruit collections from Longzhou County, Guangxi Province, China. In the protologue, the authors stated that it was clearly distinguished from its congeneric species by the large samaras. After that, A. guangxiensis is always considered as an endemic species of Guangxi (Peng & Thomas 2008, Qin & Liu 2010, Mo 2011). In 2010, it was listed as a key protected wild plant of Guangxi by the local government.