Taxonomy and phylogenetic position of Fimbristylis fusiformis, a new species of Cyperaceae from Thailand

K Wangwasit,P Chantaranothai,A.M Muasya,D.A Simpson

doi:10.3767/000651917x695209

Abstract

Fimbristylis fusiformis, an unusual new species of Cyperaceae from Thailand, is described and illustrated. This taxon has a single terminal spikelet per culm with a semi-distichous glume arrangement, bisexual flowers that lack perianth parts, and pistil with persistent style whose base is slightly swollen and trigonous nutlets with pubescent ribs. Phylogenetic reconstruction using ITS sequence data places this taxon in Abildgaardieae and sister to the rest of Fimbristylis. The species has a conservation status of Least Concern (LC).

Highlights

The genus Fimbristylis Vahl, comprising c. 300 species, occurs mostly in the tropics and subtropics with some species occurring in warm temperate regions (Govaerts et al 2007)
The glumes are generally spirally arranged in ellipsoid spikelets, more rarely distichously arranged, the bisexual flowers lack perianth parts and their deciduous styles have distinctly thickened base, and the nutlets often have distinct surface patterns
Fimbristylis is currently (e.g., Govaerts et al 2007) treated to include the segregate genus Abildgaardia Vahl, the latter only differing in having a distichous glume arrangement (Goetghebeur 1998)

Summary

Introduction

The genus Fimbristylis Vahl, comprising c. 300 species, occurs mostly in the tropics and subtropics with some species occurring in warm temperate regions (Govaerts et al 2007). Fimbristylis is currently (e.g., Govaerts et al 2007) treated to include the segregate genus Abildgaardia Vahl, the latter only differing in having a distichous glume arrangement (Goetghebeur 1998). The new species was identifiable as a member of subfamily Cyperoideae (absence of the spicoid floral structure (Simpson et al 2003), individual flowers comprising stamens and gynoecium subtended by a glume), its generic placement within Cyperoideae was not immediately obvious.

Results

Conclusion