Cyperus pseudothyrsiflorus is a plant species native to Nuevo León, New Mexico and Texas,Biota of North America Program, 2013 county distribution mapCarter, James Richard & Jones, Standley D. 1998. Rhodora 99(900): 330. It occurs in cultivated fields and other disturbed areas at elevations of less than 1000 m (3400 feet).
Cyperus pseudothyrsiflorus is a perennial herb spreading by underground rhizomes. Stems are triangular in cross-section, up to 40 cm (16 inches) tall.
It is a member of Cyperus, subgenus Cyperus, section Umbellati.Carter, James Richard & Jones, Standley D. 1997. Notes on the Cyperus retroflexus complex (Cyperaceae) with three nomenclatural proposals. Rhodora 99(900): 319-334. It was first formally described as a new variety of C. uniflorus by Georg Kükenthal in 1937,Engler, Heinrich Gustav Adolf. Das Pflanzenreich IV. 20(Heft 101): 521. 1936. but was promoted to an independent species in 1997. It is very similar to C. uniflorus,Donovan Stewart Correll & Marshall Conring Johnston. 1970. Manual of the Vascular Plants of Texas. Texas Research Foundation. which is now known as C. retroflexus.
See also List of Cyperus species
References