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

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).