Aquatic and Wetland Vascular Plants of the Northern Great Plains
62. Cyperaceae, the Sedge Family
2. Carex L. -- Sedge
4. Carex athrostachya Olney
Densely tufted, lacking rhizomes; culms trigonous, 1.5-10 dm long. Leaves
shorter than the culms, 1.5-4 mm wide, the lowest leaves bladeless; sheaths
hyaline ventrally, brownish-tinged at the base. Spikes several, bisexual,
gynaecandrous, 4-10 mm long, borne in ovoid to globose-ovoid heads 1-2 cm long;
1-3 of the lowest bracts below the inflorescence prolonged beyond the
head, occasionally merely equaling the head, other bracts reduced and inconspicuous;
pistillate scales brownish except for the green midrib, longer to shorter
than the perigynia, acute to cuspidate. Perigynia flattened to slightly
plano-convex, narrowly ovate to lanceolate, 2.5-4.5 mm long, ca. 3X longer than
wide, faintly several-nerved dorsally, fewer nerved or nerveless ventrally,
wing-margined to the base, the beak obliquely cut, serrulate below; achenes
lenticular, 1.1-1.6 mm long; stigmas 2. Jul--Aug. Wet meadows and low
prairie; uncommon in nc and nw ND; (ND and Sask. to AK, s to CO and CA).