Culms 2-15 cm × 0.3-0.5 mm. Leaves 1-6 cm × 0.4-0.6 mm. Inflorescences: spikes 1-2, ovoid (to globose), 1-5(-8) × 1-2.5 mm; bracts 1-2, longest erect, 1-3.5 cm × 0.3-0.5 mm. Spikelets: floral scales 2; 1st scale light brown to reddish brown, with greenish midvein, obtrullate to rhomboid, 0.9-1.6 × 0.3-0.6 mm, widest at mid length, long-acuminate, curving outward; 2d scale oblong, veinless (occasionally 2-4 reddish veins), 0.5-0.8 × 0.2 mm; 3d scale absent; stamens 1; anthers 0.2 mm; stigmas 2. Achenes obovoid to terete, 0.5-0.8 × 0.25-0.35 mm, 1.5-2.5 times long as wide.

Fruiting late summer-early fall. Typically on sandy soils, emergent shorelines, stream banks, ponds, ditches; 0-1500 m; Ariz., Calif., Colo., Kans., Minn., Mo., Nebr., N.Mex., Okla., Oreg., Tex., Wash., Wyo.

Common Name: awned halfchaff sedge

Duration: Annual

Nativity: Native

Lifeform: Graminoid

General: Tufted annual, not rhizomatous with solitary terete stems 2-15 cm tall, 0.5 mm thick.

Vegetative: Leaves basal, with the lower bladeless or with an involute appendage, upper with distinct glabrous blade 1-6 cm long by 0.5 mm wide; no ligules.

Inflorescence: Terminal ovoid (to globose) spike, usually 1-2, 1-5 mm long by 1-2.5 mm wide, with 1-2 bracts, the longest erect, 1-3.5 cm by 0.3-0.5 mm; spikelets with 2 floral scales, the first light brown to reddish brown with a greenish midvein, rhomboid, 1-1.5 mm by 0.5 mm, widest at midlength, long acuminate, curving outward; the second scale is oblong and veinless, 0.5 mm by 0.5 mm; the third scale is absent; achenes obovoid to terete, 0.5 mm by 0.25-0.35 mm, often 1.5-2.5 times long as wide.

Ecology: Found on sandy soils, often on stream banks, along ditches, or on shorelines to 5,000 ft (1524 m); flowers August-September.

Notes: This genus is distinguished by the presence of only 1-2 scales and glabrous leaves. This species is distinguished by the outer scale being widest at the midlength and with the veinless second scale. Rare. Difficult to say whether it is found in regional parks or not.

Ethnobotany: Unknown

Etymology: Lipocarpha comes from Greek leipo, meaning to be deficient or wanting, and karphos for chip of straw, while aristulata comes from the Latin arista for awn, so it refers to having a small awn.

Synonyms: Hemicarpha aristulata, H. micrantha var. aristulata, Lipocarpha microcephala

Editor: SBuckley, 2010