Cyperus acuminatus

{{Short description|Species of plant in Cyperaceae family native to North America}}

{{Use mdy dates|date=June 2022}}

{{speciesbox

|name = Tatertip flatsedge

|image = Cyperus acuminatus.jpg

|status =

|status_system =

|genus = Cyperus

|species = acuminatus

|authority = Torr. & Hook. ex Torr.

|synonyms_ref=

|synonyms=Cyperus cyrtolepis Torr. & Hook.

|}}

Cyperus acuminatus is a common species of sedge known by several common names, including tapertip flatsedge and pale umbrella-sedge. This plant is native to North America, where it is widespread across the Great Plains and the western United States, with scattered populations in the eastern US as well as in Saskatchewan, Tamaulipas and Coahuila.[http://apps.kew.org/wcsp/namedetail.do?name_id=235521 Kew World Checklist of Selected Plant Families][http://bonap.net/MapGallery/County/Cyperus%20acuminatus.png Biota of North America Program, 2013 county distribution map]Tucker, G. C. 1994. Revision of the Mexican species of Cyperus (Cyperaceae). Systematic Botany Monographs 43: 1–213.Espejo Serna, A. & López-Ferrari, A.R. (1997). Las Monocotiledóneas Mexicanas una Sinopsis Florística 5: 1–98. Consejo Nacional de la Flora de México, México D.F.

Cyperus acuminatus is found in wet areas from large rivers to roadside ditches. This is an annual plant with a paper-thin stem approaching {{Convert|40|cm|ftin}} in height at maximum. It may have a few thin leaves near the base. Its spherical inflorescence is one to two centimeters wide and contains several spikelets each a few millimeters long. Each spikelet has a flat layer of flowers which yield oval-shaped achene fruits, each about one millimeter long.[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242357639 Flora of North America, Vol. 23 Page 152, Cyperus acuminatus Torrey & Hooker, Ann. Lyceum Nat. Hist. New York. 3: 435. 1836. ]