Cyperus retrofractus
in J. Carey, Carices North. U.S., 519. 1847.
Herbs, perennial, cespitose. Culms with cormlike bases, sharply trigonous, 25–90 cm, glabrous proximally, minutely scabridulous distally. Leaves V-shaped, 14–40 cm × 3.5–8 mm, (pubescent on adaxial side of midrib). Inflorescences: spikes loose, obtrulloid to obdeltoid (broadest near apex, nearly as long as wide), 20–28(–34) × (12–)15–30 mm; rays 4–13, (1–)4–24 cm (longest ray shorter than bracts), glabrous; bracts 3–12, ascending at 30–45°, flat, 3–25 cm × 3–7 mm; rachilla persistent, wings 0.4–0.6 mm wide, covering 3/4 of mature achene. Spikelets 30–50, proximal one reflexed, distal ones divaricate, linear-lanceoloid, ± terete, (6.5–) 8–10(–17) × 0.5–0.7 mm; floral scales persistent, 3–6(–8), appressed, stramineous (suffused with reddish purple), 4–5-ribbed laterally, ovate-lanceolate, (4–)4.4–4.9(–5.4) × 1.3–1.5 mm; terminal scale not spinose, apex straight, excurved mucronate, or cuspidate. Flowers: anthers 0.7–1.2 mm; styles 1.5–2 mm; stigmas 2–2.5 mm. Achenes brown to brownish black, narrowly oblong, (2.2–)2.5–3 × 0.6–0.7 mm, base cuneate, apex obtuse, apiculate, surfaces puncticulate.
Phenology: Fruiting summer.
Habitat: Roadsides, pastures, disturbed sites in sandy or clayey soils
Elevation: 0–300 m
Distribution
Ala., Ark., Del., D.C., Ga., Ky., Mo., N.J., N.C., Ohio, Pa., S.C., Tenn., Va.
Discussion
For information concerning nomenclature of Cyperus retrofractus, see J. R. Carter and C. E. Jarvis (1986).
Selected References
None.