Aristida oligantha

HABIT Annual; caespitose. Culms 15–88 cm long; wiry. Culm-internodes distally glabrous. Lateral branches ample. Leaf-sheaths without keel; glabrous on surface. Leaf-sheath oral hairs lacking, or pubescent. Ligule a fringe of hairs; 0.5 mm long. Leaf-blades filiform; 10–25 cm long; 1–2 mm wide. Leaf-blade surface glabrous, or hispid; sparsely hairy. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong; 5–14 cm long; bearing few spikelets.

Spikelets solitary. Fertile spikelets sessile. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 18–25 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 1 mm long; pubescent; acute.

GLUMES Glumes dissimilar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 18–25 mm long; 1 length of upper glume; membranous; 3–7 -veined. Lower glume apex acuminate; muticous, or awned; 1 -awned. Lower glume awn 0.5 mm long. Upper glume lanceolate; 18–25 mm long; 1.1 length of adjacent fertile lemma; membranous; 1 -veined. Upper glume lateral veins absent. Upper glume apex dentate; 2 -fid; acute; awned; 1 -awned. Upper glume awn 10–15 mm long.

FLORETS Fertile lemma linear; subterete; 16–28 mm long; coriaceous; without keel; 3 -veined. Lemma surface scabrous; rough above. Lemma margins convolute; covering most of palea. Lemma apex awned; 3 -awned. Principal lemma awn 3-branched; spreading; with 30–70 mm long limb; without a column. Lateral lemma awns spreading as much as principal; 30–70 mm long; subequal to principal.

FLOWER Anthers 3.

DISTRIBUTION North America: northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, and southeast USA.

NOTES Aristideae. Gr Tex 1993.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.