Molecular phylogeny and morphology reveal a new epiphytic species of Habenaria (Orchidaceae; Orchideae; Orchidinae) from Nepal.

Bhakta Bahadur Raskoti,Rita Ale,Paulo Takeo Sano

doi:10.1371/journal.pone.0223355

Abstract

Habenaria is almost cosmopolitan in distribution having predominantly terrestrial orchids, however; a remarkable epiphytic species with some unique morphological characters was collected from Nepal. We conducted a molecular phylogeny of this unusual Habenaria species using nuclear (ITS) and chloroplast (matK, rbcl) DNA sequence regions to infer its systematic position. Our molecular analyses and morphological treatment recognized this newly collected plant as an undescribed species. This species is described here which is closely related to Habenaria plurifoliata but can be distinguished by having its multiple growing callus-shaped tuber, smaller stature with short stem, longer and wider oblanceolate leaves, peduncle with a foliaceous bract and only one sterile bract, lateral sepals oblong, obtuse, petal apex obtuse, lateral lobes of lip spreading upwards, spur not exceeding the ovary and pedicel.

Highlights

Habenaria Willd. (Orchidinae, Orchidoideae, Orchidaceae) is a large genus having more than 891 species [1]
There was no significant difference in topologies of individual marker and between nrITS and chloroplast; they were at different levels of resolution
The relationships in the resulting cladograms of Habenaria (Fig 1), generally agree with those recovered in the previous phylogenetic analyses [6, 7, 8, 9, 22]

Summary

Introduction

Habenaria Willd. (Orchidinae, Orchidoideae, Orchidaceae) is a large genus having more than 891 species [1]. The vast majority species of Habenaria are terrestrial orchids and nearly cosmopolitan, occurring in the tropical, subtropical, temperate and alpine regions [2,3,4,5]. Habenaria as currently delimited is characterized by having undivided tuber, spurred lip, long column, U-shaped wide anther connective, long caudicle, naked viscidium, long and free stigma drawn out at the entrance of spur [2,3]. Molecular phylogeny performed by different authors that included Habenaria and its alliance Et W.T. Jin, Bonatea Willd., Diplomeris D. Despite of past and recent progress on phylogeny of Habenaria and its alliance [6, 7, 8, 9], problems remain to be addressed to solve relationships mainly between Old World and New World species [6, 7]

Methods

Results

Conclusion