Natural History Museum of Guangxi, Nanning 530012, People’s Republic of China.

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. In Ailanthus, the samara morphology is placed a high value on distinguishing species, including both living and fossil species (Nooteboom 1962, Corbett & Manchester 2004). The examination of the cited collections of A. guangxiensis, including the holotype (Fig. 1), shows that the samara is 12.9–14.8 × 3.6–4.1 cm. Although it is much larger than that of any other Chinese species of Ailanthus (usually less than 8 cm long), it does not beyond the range of A. integrifolia (11–22 × 2.5–5 cm), which has geographic distribution extending from India, Vietnam, the Philippines