A remarkable new species of Liparis (Orchidaceae) from China and its phylogenetic implications.

In the present study, we formally describe Liparis pingxiangensis as a new species from Guangxi, China on the basis of morphological and molecular phylogenetic analyses. It is easily distinguished from closely related species by strongly curved column without column wings, and broadly rhombic-elliptic lip with 2 uncinate calli at the base. In particular, it differs most markedly from its congeners in possessing two pollinia attached by long and prominent caudicles (not stipes), to a distinct sticky disc. This type of pollinarium, as far as we know, is not found in any other species of Liparis, and is also unique among the orchids with waxy pollinia. We then proceeded to a phylogenetic analysis to ascertain the systematic position of this enigmatic species. Molecular study based on nuclear ribosomal ITS and plastid matK DNA sequence data supports L. pingxiangensis as a distinct species, which forms an independent lineage sister to L. nervosa and its allies (93% BS, 1.00 BPP). In the light of previous work, the findings have important implications for a better understanding of the well-supported pattern mainly based on vegetative features in Malaxideae.