Aristida basiramea

HABIT Annual. Culms erect; 30–50 cm long. Culm-internodes smooth, or scaberulous. Lateral branches lacking. Leaf-sheaths glabrous on surface. Ligule a fringe of hairs. Leaf-blades flat, or involute; 7–15 cm long; 0.7–1.5 mm wide. Leaf-blade surface scabrous; rough adaxially; pilose; sparsely hairy; hairy adaxially.

INFLORESCENCE Inflorescence a panicle; terminal and axillary. Axillary inflorescences enclosed.

Panicle open; linear; 5–10 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 7–8 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.3 mm long; pubescent; obtuse.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma. Lower glume linear; 10–12 mm long; 0.8 length of upper glume; membranous; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acuminate; mucronate. Upper glume linear; 12–15 mm long; 1.2–1.5 length of adjacent fertile lemma; membranous; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex acuminate; mucronate.

FLORETS Fertile lemma linear; subterete; 10 mm long; coriaceous; without keel; 3 -veined. Lemma midvein scabrous. Lemma margins convolute; covering most of palea. Lemma apex awned; 3 -awned. Principal lemma awn 3-branched; ascending and briefly coiled at base of limb; with 10–15 mm long limb. Lateral lemma awns spreading as much as principal; 5–10 mm long; shorter than principal.

FLOWER Anthers 3.

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

NOTES Aristideae. N Amer Fl 1994.

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