Common Name: inflatedscale flatsedge

Duration: Perennial

Nativity: Native

Lifeform: Graminoid

General: Tufted perennial with rhizomes 0.5-3.5 cm long, about 1 cm in diameter, with three sided stems 20-100 cm tall, 0.8-2.5 mm in diameter, smooth.

Vegetative: Leaves 5-10, v-shaped to flanged v-shaped, 10-70 cm long, 2-7 mm wide, margins and keel rough to the touch.

Inflorescence: Densely cylindric spikes, 1-6, 6-30 mm long, 5-11 mm wide, subtending inflorescence bracts 4-7, 1-16 cm long, v-shaped, slightly ascendent to horizontal; rays 3-12, 0.5-5 cm, spikelets 20-80, 3-5 mm long, 1-1.5 mm wide, ellipsoid, roughly quadrate, flexuous, light green to straw colored, often red-spotted; persistent scales 1-2, 2.5-3.5 mm long, 1.5-2.5 mm wide, elliptic to ovate, obtuse apex, laterally 3-nerved, often red-speckled and straw to golden brown; achenes 1.8-2 mm long, about 1 mm wide, three sided, broadly ellipsoid, sessile base, concave face, dark brown to reddish brown.

Ecology: Found on gravelly to sandy soils often in dry disturbed sites from 4,000-6,000 ft (1219-1829 m); flowers July-October.

Notes: Recognized by the dense, cylindric, straw colored to golden brown spikes, that are sessile or borne on short rays to 7 cm long. It can be confused with C. pallidicolor but has dense spikes and grows at lower elevations.

Ethnobotany: Unknown

Etymology: Cyperus is from the Greek word meaning sedge, while aggregatus means clustered together.

Synonyms: Cyperus cayennensis, Cyperus flavus, Cyperus huarmensis, Cyperus obesus, Mariscus cayennensis, Mariscus flavus

Editor: SBuckley, 2010

Of trop. Amer., with the spikes ovoid and all sessile, has been collected as a waif in N.J. and Pa. (C. cayennensis)

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.