Cyperus

Linnaeus

Sp. Pl. 1: 44. 1753

,

Gen. Pl. ed. 5, 26. 1754

Common names: Umbrella-sedge flatsedge
Etymology: Greek kupeiros, name for Eurasian Cyperus longus Linnaeus
Treatment appears in FNA Volume 23. Treatment on page 141. Mentioned on page 7, 154, 162, 163, 164, 168, 170, 184.
Herbs, perennial or less often annual, cespitose or not, rhizomatous, stoloniferous, rarely tuberous. Culms solitary or not, trigonous or round, glabrous or scabridulous with extrorse or antrorse (rarely retrorse) prickles. Leaves usually basal; ligules absent; blades keeled abaxially, flat, V-, or inversely W-shaped in cross section. Inflorescences terminal, rarely pseudolateral, 1st order subumbellate to capitate, 2d order with spicate or digitately arranged spikelets, rarely a solitary spikelet; spikelets 1–150; 1st order rays unequal (rarely equal) in length, produced singly from the axils of inflorescence bracts; involucral bracts 1–22, spirally arranged at culm apex, spreading to erect, leaflike. Spikelets: scales to 76, distichous, each subtending flower, cylindric to compressed, borne spicately or digitately at ends of rays (occasionally proliferous). Flowers bisexual [rarely unisexual], in axils of distichous floral scales, bases often decurrent onto rachilla as ± hyaline wings; perianth absent; stamens 1–3; styles linear, 2–3-fid, base deciduous or persistent; stigmas 2–3. Achenes biconvex, flattened, or trigonous.

Distribution

Pantemperate and tropical.

Discussion

Species ca. 600 (96 in the flora).

Key

1 Stigmas 2 (3 in C. serotinus); achenes biconvex. > 2
1 Stigmas 3; achenes trigonous, plano-convex, or terete. > 3
2 Achenes laterally flattened, borne with edge toward rachilla. Cyperus subg. Pycreus
2 Achenes dorsiventrally flattened, borne with face toward rachilla. Cyperus subg. Juncellus
3 Spikelets borne in digitate clusters (rarely singly) or in umbellate or glomerulate heads. Cyperus subg. Pycnostachys
3 Spikelets borne in spikes on conspicuous rachis. > 4
4 Rachilla continuous or articulate only at base. Cyperus subg. Cyperus
4 Rachilla articulate at base of each scale, mature spikelet disarticulating into segments consisting of scale, internode, and rachilla wings. Cyperus subg. Diclidium
Facts about "Cyperus"
AuthorGordon C. Tucker* +, Brian G. Marcks* + and J. Richard Carter * +
AuthorityLinnaeus +
Common nameUmbrella-sedge + and flatsedge +
DistributionPantemperate and tropical. +
EtymologyGreek kupeiros, name for Eurasian Cyperus longus Linnaeus +
IllustrationPresent +
Illustration copyrightFlora of North America Association +
IllustratorYevonn Wilson-Ramsey +
Publication titleSp. Pl. + and Gen. Pl. ed. +
Publication year1753 + and 1754 +
Referencecarter1984a +, corcoran1941a +, denton1978b +, horvat1941a +, marcks1972a +, marcks1974a +, mcgivney1938a +, tucker1983a +, tucker1993a + and tucker1994a +
Source xmlhttps://jpend@bitbucket.org/aafc-mbb/fna-data-curation.git/src/f50eec43f223ca0e34566be0b046453a0960e173/coarse grained fna xml/V23/V23 225.xml +
Taxon familyCyperaceae +
Taxon nameCyperus +
Taxon parentCyperaceae +
Taxon rankgenus +
VolumeVolume 23 +