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Systematics of the genus Salweenia (Leguminosae) from Southwest China with discovery of a second species
Author(s) -
Yue Xue-Kun,
Yue Ji-Pei,
Yang Li-Er,
Li Zhi-Min,
Sun Hang
Publication year - 2011
Publication title -
taxon
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 81
eISSN - 1996-8175
pISSN - 0040-0262
DOI - 10.1002/tax.605012
Subject(s) - vicariance , monophyly , biology , genus , systematics , range (aeronautics) , phylogenetic tree , clade , botany , taxonomy (biology) , zoology , evolutionary biology , ecology , biochemistry , materials science , gene , composite material
Salweenia (Leguminosae) has long been defined as a monotypic genus. In this study we carried out comprehensive studies on populations of S. wardii Baker f. across its distribution range. The results showed that this species diverged into two distinct groups: plants from the Yalong Jiang valley have linear leaflets 0.07–0.14 cm wide and relatively flattened legumes, as well as a 2A karyotype asymmetry, whereas plants from the Nu Jiang and Lancang Jiang drainages have lanceolate leaflets 0.20–0.34 cm wide, undulant legumes, and a 1A karyotype asymmetry. Furthermore, molecular phylogenetic analysis of four chloroplast DNA markers ( trnL‐F, rpl32‐trnL, psbA‐trnH, trnS‐G ) recovered two reciprocally monophyletic clades among accessions of plants from these two areas respectively. We therefore recognize individuals of S. wardii in the Yalong Jiang valley as a separate species, S. bouffordiana sp.nov. Salweenia thus contains two allopatrically distributed species and the genus is no longer monotypic. The origin of the disjunction between the two species is briefly discussed and it is hypothesized to have come about through vicariance, resulting of several historic river separations, reversal and capture events estimated to have taken place during the Pleistocene.