Cyperus bipartitus

Torrey

Ann. Lyceum Nat. Hist. New York 3: 257. 1836

Common names: Shining flatsedge
Illustrated
Synonyms: Cyperus rivularis Kunth
Treatment appears in FNA Volume 23. Treatment on page 161. Mentioned on page 142, 159.

Herbs, annual, densely cespitose, with fibrous roots. Culms roundly trigonous, 3–25(–30) cm × 0.3–1.4 mm, glabrous. Leaves 1–3, V-shaped, 1–8 cm × 1–2 mm. Inflorescences: spike 1, loosely ovoid, compressed, 7–14 × 9–14 mm; rays 1–4, to 2(–3) cm; bracts 2–3, horizontal to ascending at 30(–45)°, V-shaped to flat, 1–12 cm × 0.5–1.5 mm. Spikelets 3–5(–8), flattened, oblong to oblong-lanceoloid, 8–18 × 2–2.6(–3) mm; floral scales (6–)10–26(–32), closely imbricate, laterally light to dark brown, medially light brown, laterally ribless, medially 2–3-ribbed, 2-keeled, oblong to ovate, 1.9–2.7 × 1.8–2.3 mm, apex obtuse. Flowers: stamens 2–3; anthers 0.4–0.5 mm, connective not prolonged; styles 0.6–1 mm; stigmas 1–1.5 mm. Achenes black, network of ridges forming isodiametric or square cells, sessile, obovoid to ovoid, 1–1.3(–1.5) × (0.6–)0.8 mm, apex apiculate, surfaces minutely punctate.


Phenology: Fruiting summer.
Habitat: Emergent shorelines, ditches, puddles, often in disturbed places
Elevation: 0–1500 m

Distribution

V23 255-distribution-map.jpg

Ont., Que., Ala., Ariz., Ark., Calif., Colo., Conn., Del., D.C., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Mexico, Central America, South America.

Discussion

Selected References

None.

Lower Taxa

None.

... more about "Cyperus bipartitus"
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
Torrey +
Undefined subg. Pycreus +
Shining flatsedge +
Ont. +, Que. +, Ala. +, Ariz. +, Ark. +, Calif. +, Colo. +, Conn. +, Del. +, D.C. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, Nebr. +, Nev. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, N.C. +, N.Dak. +, Ohio +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Tex. +, Utah +, Vt. +, Va. +, Wash. +, W.Va. +, Wis. +, Mexico +, Central America +  and South America. +
0–1500 m +
Emergent shorelines, ditches, puddles, often in disturbed places +
Fruiting summer. +
Ann. Lyceum Nat. Hist. New York +
Illustrated +
Cyperus rivularis +
Cyperus bipartitus +
Cyperus subg. Pycreus +
species +