Cyperus erythrorhizos
Descr. Gram., 20. 1817.
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, oblongovate 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
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
"shortened" is not a number.