Herbs, perennial, rhizomatous. Culms trigonous, (30-)45-80 cm × (0.8-)1.2-2.2 mm, glabrous. Leaves flat to V-shaped, becoming trigonous apically, 15-30 cm × 0.5-3.2 mm. Inflorescences: spikes oblong-cylindric, densely spicate, ± truncate at base, (9-)12-22 × (4-)6-12 mm; rays 2-4(-5), (1.5-)2.5-6 cm; bracts 4-6, longest erect or nearly so, larger ones flat or V-shaped, smaller capillary, trigonous, 3-24 cm × 0.4-3.6 mm; rachilla ± deciduous, wings 0.2-0.4 mm wide. Spikelets (10-)20-60, oblong to linear-lanceoloid, compressed-quadrangular, 3-9 × 2-3.4 mm; floral scales deciduous, 2-4(-8), spreading, medially green, laterally stramineous, dull whitish or pale reddish brown, often red-dotted laterally, (3-)7-9-ribbed, ovate-lanceolate, (2-)2.2-2.8(-3) × (1-)1.2-1.8 mm, apex acute, weakly 3-dentate, mucro 0.2-0.6 mm, with apical tuft of crystalline prickles. Flowers: anthers 0.4-0.9 mm; styles 1-1.4 mm; stigmas 1-1.6 mm. Achenes brown, ± stipitate, broadly ellipsoid, 1.4-1.5(-1.6) × 0.8-0.9 mm, 0.1 × 0.1-0.2 mm, apex ± truncate, apiculate, surfaces papillose.

Fruiting late summer. Seepage slopes in montane forests; 1000-1500 m; Ariz., N.Mex.; Mexico.

Common Name: Wright's flatsedge

Duration: Perennial

Nativity: Native

Lifeform: Graminoid

General: Rhizomatous perennial with three sided stems 45-80 cm tall, 1-2 mm in diameter, rhizomes 0.5-3 cm long, tuberlike, 3-6 mm in diameter and covered in reddish brown scales.

Vegetative: Leaves 2-3, 15-30 cm long, 0.5-3 mm wide, flat to v-shaped, becoming three edged near the apex, margins and keel rough to the touch throughout or smooth in the basal half.

Inflorescence: With 4-6 subtending bracts, 3-24 cm long, 0.4-3.5 m wide, larger ones flat or v-shaped, smallest capillary, longest erect or nearly so, others ascendent; rays 2-4, 2.5-6 cm,spikes 12-22 mm long, 6-12 mm wide, densely oblong-cylindric, with rachis 10-16 mm long, spikelets 20-60, 3-9 mm long, 2-3.5 mm wide, oblong to linear-lanceolate, compressed-quadrate and borne at right angles, lower spikelets never reflexed, 2-4 deciduous scales, these 2-3 mm long, 1-2 mm wide, ovate-lanceolate with a mucro 0.2-0.6 mm long and apical tuft of crystalline prickles, dull whitish to pale reddish, to stramineous brown; achenes brown about 1.5 mm long, three sided, broadly ellipsoid with papillose surface.

Ecology: Found in moist soils near seeps, springs, and along moist ledges and rich soils of canyons from 3,500-5,000 ft (1067-1524 m); flowers August-October.

Notes: Distinguished by the combination of erect to ascendent inflorescence bracts, the densely oblong-cylindric spikes and acute, straw colored to light reddish brown scales.

Ethnobotany: Unknown

Etymology: Cyperus is from the Greek word meaning sedge, while dipsaceus is from Greek dipsa for thirst.

Synonyms: Cyperus wrightii

Editor: SBuckley, 2010