''Rhynchospora'' (beak-rush or beak-sedge) is a genus of about 400 species of

sedges The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus ''Carex'' wi ...

with a cosmopolitan distribution. The genus includes both annual and perennial species, mostly with erect 3-sided stems and 3-ranked leaves. The achenes bear a beak-like tubercule (hence the name “beak-rush”, although the plants are

, not rushes) and are sometimes subtended by bristles. Many of the species are similar in vegetative appearance, and mature fruits are needed to make a positive identification. The inflorescences (spikelets) are sometimes subtended by bracts which can be leaf-like or showy.Flora of North America, Vol. 23 Page 200, ''Rhynchospora'' Vahl, Enum. Pl. 2: 229. 1805 (as ''Rynchospora'')
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Ecology

''Rhynchospora'' occurs on all continents except Antarctica, but is most diverse in the neotropics.Thomas, W.W. 1992. A synopsis of ''Rhynchospora'' (Cyperaceae) in Mesoamerica. ''Brittonia'' 44:14–44. It is most frequent in sunny habitats with wet, acidic soils.Kral, R. 2002. ''Rhynchospora''. In: Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 15+ vols. New York and Oxford. Vol. 23 pp. 200-239. In marshes and savannas, ''Rhynchospora'' may be the dominant form of vegetation.

Taxonomy

Contemporary taxonomic treatments include ''Rhynchospora'' and the related genus ''Pleurostachys'' in the tribe Rhynchosporae, a well-supported clade within Cyperaceae.Muasya, A. M., J. Bruhl, D. A. Simpson, A. Culham and M. W. Chase. 2000. Suprageneric phylogeny of Cyperaceae: A combined analysis. pp. 593–601. In: K. Wilson and D. Morrison (eds.) Monocots: Systematics and Evolution. CSIRO: Melbourne. The most comprehensive monograph of the genus Kükenthal, G. 1949-1951. Vorarbeiten zu einer Monographie der Rhynchosporoideae. ''Rhynchospora''. Bot. Jahrb. Syst. 74, 75 divides ''Rhynchospora'' into two subgenera and 29 sections. A recent molecular analysis Thomas W.W., A.C. Araujo, and M.V. Alves. 2009. A Preliminary Molecular Phylogeny of the Rhynchosporae (Cyperaceae). Botanical Review 75:22-29. identifies two primary clades within the genus, with well-supported subgroups that agree with several of the sections identified by Kükenthal. However, this molecular analysis also suggests that ''Pleurostachys'' is embedded within one of the primary clades of ''Rhynchospora'' and that several of the recognized sections are not

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic ...

. ;Selected species: *'' Rhynchospora alba'' - White beak-sedge.

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

, North America *''

Rhynchospora caduca ''Rhynchospora caduca'', commonly called anglestem beaksedge, is a species of flowering plant in the sedge family (Cyperaceae The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The fa ...

'' - Southeast North America *''

Rhynchospora californica ''Rhynchospora californica'' is a species of sedge known by the common names California beaked-rush and California beaksedge. It is endemic to California where it is mainly distributed in the northwestern corner of the state south to the San F ...

'' - California beaked-rush, occurring in Marin and

Sonoma County, California Sonoma County () is a county (United States), county located in the U.S. state of California. As of the 2020 United States Census, its population was 488,863. Its county seat and largest city is Santa Rosa, California, Santa Rosa. It is to the n ...

*''

Rhynchospora capillacea ''Rhynchospora capillacea'' is a species of sedge known by the common names needle beaksedge, slender beakrush and needle beakrush. It is native to eastern North America from Labrador to Alberta, and south to Texas. It grows in wet, usually cal ...

'' - Slender beakrush. Eastern North America *''

Rhynchospora capitellata ''Rhynchospora capitellata'' is a species of sedge known by the common names brownish beaksedge and brownish beaked-rush. It is native to eastern North America and a few spots in the western United States. It grows in wet habitat, such as swamp ...

'' - Brownish beak-sedge *''

Rhynchospora colorata ''Rhynchospora colorata'', also known as starrush whitetop, white star sedge and white-topped sedge, is a perennial sedge with white bracts, giving it the appearance of white petals with long, green points. It is native to southeastern North Amer ...

'' - White star sedge. Southeast North America. *''

Rhynchospora fusca ''Rhynchospora fusca'' (vernacular name: brown beak-sedge) is a species of sedge belonging to the family Cyperaceae The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is l ...

'' - Brown beak-sedge.

. *''

Rhynchospora glomerata ''Rhynchospora'' (beak-rush or beak-sedge) is a genus of about 400 species of sedges with a cosmopolitan distribution. The genus includes both annual and perennial species, mostly with erect 3-sided stems and 3-ranked leaves. The achenes bear a ...

'' - Clustered beak-sedge. North America.''Rhynchospora glomerata'' (L.) Vahl
USDA Plants Profile. 23 Nov 2011 *'' Rhynchospora inexpansa'' - Southeastern North America and West Indies *''

Rhynchospora knieskernii ''Rhynchospora knieskernii'' is a rare species of sedge known by the common name Knieskern's beaksedge. It is endemic to the state of New Jersey in the United States, where it occurs naturallyin the Pine Barrens. Reports have cited it present in ...

'' - Knieskern's beak-sedge. *'' Rhynchospora longisetis'' *'' Rhynchospora macrostachya'' - Tall horned beaksedge. Eastern North America. *'' Rhynchospora megalocarpa'' -

Southeastern United States The Southeastern United States, also referred to as the American Southeast or simply the Southeast, is a geographical region of the United States. It is located broadly on the eastern portion of the southern United States and the southern po ...

*'' Rhynchospora megaplumosa '' - Florida *'' Rhynchospora nervosa'' - Tropical

New World The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. ...

. *'' Rhynchospora rariflora'' - Southeastern North America, West Indies, Central America *'' Rhynchospora scirpoides'' - North America *'' Rhynchospora waspamensis'' -

References

External links

interactive identification key

Other sources

* Acevedo-Rodríguez, P. & Strong, M.T. (2005). Monocotyledons and Gymnosperms of Puerto Rico and the Virgin Islands. Contributions from the United States National Herbarium 52: 1-415. * Gale, S. 1944. ''Rhynchospora'' sect. ''Eurhynchospora'' in Canada, the United States and the West Indies. Rhodora 46: 80–134, 159–197, 255–278. * Kral, R. 1996. Supplemental notes on ''Rhynchospora crinipes'' and related species in sect. ''Fuscae'' (Cyperaceae). Sida 17: 385–411. * Strong, M.T. (2006). Taxonomy and distribution of ''Rhynchospora'' (Cyperaceae) in the Guianas, South America. Contributions from the United States National Herbarium 53: 1-225. * Thomas, W. W. 1994. 1. ''Rhynchospora'' Vahl. 6: 404–422. In G. Davidse, M. Sousa Sánchez & A.O. Chater (eds.) Flora Mesoamericana. Universidad Nacional Autónoma de México, México, D. F. {{Taxonbar, from=Q164202 Cyperaceae genera Taxa named by Martin Vahl