Thrixspermumtaeniophyllum (Orchidaceae, Epidendroideae), a new species from southwest China, based on molecular and morphological evidence.

ABSTRACT

Thrixspermumtaeniophyllum is described as a new orchid species from Wenchuan County, Sichuan Province of southwest China. It is morphologically similar to T.japonicum, but it differs from the latter in having branched stems, slightly fleshy strap-shaped leaves, longer inflorescences with 3-6 flowers and a capitate gynandrium with a lip-shaped mouth opening. Its species status is also supported by molecular phylogenetic analyses, based on nuclear ribosome internal transcribed spacer (nrITS) and three chloroplast DNA fragments (matK, psbA-trnH and trnL-F), which showed distinct systematic boundaries from the most morphologically similar T.japonicum and their morphological relatives T.saruwatarii and T.pygmaeum.