''Rhynchospora'' (beak-rush or beak-sedge) is a genus of about 400 species of
sedges with a
cosmopolitan distribution
In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The extr ...
. 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
sedges, 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 gr ...
.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 Continent#Subcontinents, subcontinent of Eurasia ...
, North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...
*'' Rhynchospora caduca'' - Southeast North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...
*'' Rhynchospora californica'' - California beaked-rush, occurring in Marin and Sonoma County, California
Sonoma County () is a 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. It is to the north of Marin County and the south of Mendoci ...
*'' Rhynchospora capillacea'' - Slender beakrush. Eastern North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...
*'' Rhynchospora capitellata'' - Brownish beak-sedge
*'' Rhynchospora colorata'' - White star sedge. Southeast North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...
.
*'' Rhynchospora fusca'' - Brown 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 Continent#Subcontinents, subcontinent of Eurasia ...
.
*'' Rhynchospora glomerata'' - Clustered beak-sedge. North America.[''Rhynchospora glomerata'' (L.) Vahl](_blank)
USDA Plants Profile. 23 Nov 2011
*'' Rhynchospora inexpansa'' - Southeastern North America and West Indies
*'' Rhynchospora knieskernii'' - 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 List of regions in the United States, region of the United States. It is located broadly on the eastern portion of the south ...
*'' 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'' - 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. ...
.
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