Cyperus hypopitys G. C. Tucker

Cyperus hypopitys can be recognized by the combination of reddish floral scales and sharp-angled culms.

Herbs, perennial, rhizomatous, tending to form small clumps by basal offshoots. Culms triquetrous, bulbous, thickened, (20–)30–80(–90) cm × 0.7–1.2 mm, glabrous proximally, becoming trigonous strongly scabridulous on distal angles, clothed with persistent reddish fibers at base. Leaves flat to V-shaped, 20–45 cm × 2–4 mm. Inflorescences: spike 1, loosely ovoid to ovoid-ellipsoid, (1.5–)2.5–7 × (1–)1.5–3.5 cm; rays (1–)2–4, to 6 cm; 2d order rays rarely present, to 2 cm; 3d order rays absent; bracts (2–) 3, ± horizontal, 1–15(–21) cm × 0.4–3.5 mm; rachilla deciduous, wings hyaline, 0.3–0.4 mm wide. Spikelets (3–)8–26, reddish to reddish brown, linear, compressed-quadrangular, 8–18 × (2.4–)2.8–4 mm; floral scales deciduous, 6–16, laterally reddish, medially green, occasionally red-glandular, laterally strongly 3(–4)-ribbed, medially punctate, 1–3-ribbed, ovate-lanceolate, (2.6–)2.8–3.3 × (1.4–)1.6–1.8(–2) mm, apex weakly 3-dentate, mucronulate, with tuft of crystalline prickles, medially glabrous. Flowers: anthers 0.8–1.1 mm; styles 1–1.4 mm; stigmas 1–1.4 mm. Achenes brownish, stipitate, ellipsoid, 1.6–2 × (0.7–)0.9–1 mm, base whitish, stipe to 0.1–0.2 mm, apex obtuse, slightly apiculate, surfaces papillose.

Ariz.; Mexico (Chihuahua, Durango, Sinaloa, Sonora).

Fruiting late summer–early fall.

Canyons in pine forests; of conservation concern; 500–1500m.

Cyperus hypopitys is a species of sedge that is native to southern parts of North America.