Hylodesmum laxum (Candolle, 1825) H. Ohashi & R. R. Mill, 2000

Li, Huai-Cheng, Zhao, Xue-Li, Gao, Xin-Fen & Xu, Bo, 2019, Molecular phylogeny of the genus Hylodesmum (Fabaceae), Phytotaxa 403 (3), pp. 221-229 : 226

H. laxum group

There are four species, i.e., H. leptopus (Gray ex Bentham 1852: 226) H.Ohashi & R.R.Mill (2000: 179) , H. laxum ( Candolle 1825: 102) H.Ohashi & R.R.Mill (2000: 178) , H. laterale ( Schindler 1926: 258) H.Ohashi & R.R.Mill (2000: 177) , and H. densum (C.Chen & X.J.Cui in Cui et al. 1987: 306) H.Ohashi & R.R.Mill (2000: 176) within this group. Our research sampled three out of the four species, except for H. densum . These three species were clustered in all analyses with high support values, which is in accordance with the morphological characteristics, i.e., wings and keel petals distinctly clawed at base. Within the clade, H. leptopus diverged earlier than the other two species, and formed a small clade. In morphology, H. leptopus obviously differed from the other two species based on the shape and size of the articles, and the length of the fruiting pedicel and stipe. Molecular and morphological evidence was mutually verified. Hylodesmum laxum and H. laterale formed a clade with high support values, which showed their relatively closer relationship. Morphologically, they were very similar and their articles of legume were slightly broadly subobovate and the main lateral veins of the leaflets were not straight to the leaf margin. Overall, the molecular evidence supports the division of the H. laxum group.