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
![V23 285-distribution-map.jpg](/w/images/7/74/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
"shortened" is not a number.