Cyperus erythrorhizos

Muhlenberg

Descr. Gram., 20. 1817

Common names: Red-rooted flatsedge
Synonyms: Cyperus cupreus J. Presl & C. Presl Cyperus erythrorhizos var. cupreus (J. Presl & C. Presl) Kükenthal Cyperus occidentalis Gandoger Cyperus washingtonensis
Treatment appears in FNA Volume 23. Treatment on page 172. Mentioned on page 147, 171, 184.

Herbs, annual, cespitose. Culms trigonous to roundly trigonous, (0.5–)5–25(–105) cm × 1–2.5(–7.5) mm, glabrous. Leaves flat to inversely W-shaped, 5–25(–90) cm × 2–5(–11) mm. Inflorescences: spikes 1–3(–6), rather densely cylindric-ovoid, (4–)10–30(–45) × (6–)10–16(–23) mm; rays 2–6(–12), 1–8(–28) cm; bracts (3–)5–7(–11), horizontal to ascending at 30°, inversely W-shaped, (3–)10–20(–70) cm × 1–3(–12) mm; rachilla persistent, at maturity becoming laterally free, remaining firmly attached proximally, wings 0.3(–0.4) mm wide. Spikelets (20–)40–80, linear, quadrangular, 3–8(–11) × 1–1.5 mm; floral scales deciduous, 6–16(–30), appressed, laterally light brown with reddish speckles, medially greenish, laterally ribless, medially 3-ribbed, oblong-ovate to obovate, quadrangular to subterete, 1.3–1.5 × 0.8–1.2 mm, apex obtuse, mucronulate. Flowers: anthers 0.2–0.3 mm, connectives 0.1 mm; styles 0.7–0.8 mm; stigmas 0.4 mm. Achenes light grayish to brown, sessile, ovoid, (0.4–)0.7–1 × 0.4–0.6 mm, apex rounded, apiculate, surfaces glabrous.


Phenology: Fruiting summer.
Habitat: Emergent shorelines
Elevation: 0–1500 m

Distribution

V23 285-distribution-map.jpg

Man., Ont., Ala., Ariz., Ark., Calif., Conn., Del., D.C., Fla., 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, Va., Wash., W.Va., Wis., Mexico (Baja California).

Discussion

Selected References

None.

Lower Taxa

None.

... more about "Cyperus erythrorhizos"
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
Muhlenberg +
Red-rooted flatsedge +
Man. +, Ont. +, Ala. +, Ariz. +, Ark. +, Calif. +, Conn. +, Del. +, D.C. +, Fla. +, 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 +, Va. +, Wash. +, W.Va. +, Wis. +  and Mexico (Baja California). +
0–1500 m +
Emergent shorelines +
Fruiting summer. +
Descr. Gram., +
Cyperus cupreus +, Cyperus erythrorhizos var. cupreus +, Cyperus occidentalis +  and Cyperus washingtonensis +
Cyperus erythrorhizos +
Cyperus subg. Cyperus +
species +