Schaffner's Hairsedge

Herbs, annual, cespitose, diminutive. Culms at most to 7 cm. Leaves overtopping scapes; sheaths pale, shorter than blade; blades spreading or curving outward, filiform, 0.5 mm wide, flat to slightly involute, margins thickened, scabrid. Inflorescences: spikelets solitary, either atop short, stiff glabrous scapes or very short-scaped to subsessile and clustered at plant base, pale with greenish scale midribs, ovoid, 5 mm; involucral bracts 2, the proximal strongly bladed, much exceeding spikelet. Spikelets: fertile scales lanceolate, keeled, 3.5 mm, keel excurrent as mucro or cusp. Flowers: stamens 3; anthers narrowly oblong, 0.5 mm. Achenes yellowish or pale gray, ribs prominent, trigonous obovoid, 1 mm, faces evenly, finely transversely rugose.

N.Mex.; n Mexico.

Fruiting all year.

Sandy or gravelly clearings in pine or oak-pine; 0–3000m.

Scirpus schaffneri Boeckeler, Bot. Jahrb. Syst. 7: 275. 1886; S. pringlei Britton

Bulbostylis schaffneri (Bock.) Clarke, Kew Bull. Add. Ser
8 : 26. 1908.
Scirpus Schaffneri Bock. Bet. Jahrb. 7 : 275. 1886.
Scirpus Pringlei Britton, Bull. Torrey Club 15: 103. 1888. (Chihuahua, Mexico.)
Cespitose dwarf annual ; culms 2-4 cm. high (or more frequently reduced to basal spikelets), filiform, hispid, sulcate; leaves hispid, setaceous, 2-3 cm. long; inflorescence a single ovate, compressed, acute, loosely-flowered spikelet 5 mm. long (much exceeded by the lowest bract) ; scales stramineous to chestnut-brown, mucronate and strongly keeled, becoming saccate at the base in maturity; achene broadly obovate, sharply trigonous, truncate to depressed at the apex, rugose-undulate, stramineous at maturity; style-base light brown, depressed-conic; style slender, 1.0 mm. long below the branches; stamens 3, the anthers 0.25 mm. long.
Type locality : San Luis Potosi. Distribution : Chihuahua and San Luis Potosi.