Aristida purpurea

HABIT Perennial; caespitose. Culms slender; 25–70 cm long. Leaves mostly basal, or basal and cauline. Leaf-sheaths glabrous on surface, or puberulous. Leaf-sheath oral hairs pubescent, or ciliate. Ligule a fringe of hairs; 0.3–0.6 mm long. Leaf-blades involute; 3–18 cm long; 0.7–2 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear; nodding; 10–25 cm long. Primary panicle branches appressed, or spreading. Panicle branches capillary; flexuous.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 11–15 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.5 mm long; pubescent; pungent.

GLUMES Glumes dissimilar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 6–8 mm long; 0.5 length of upper glume; membranous; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 11–15 mm long; 1.1–1.3 length of adjacent fertile lemma; membranous; 1 -veined. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma linear; subterete; 10–12 mm long; coriaceous; without keel; 3 -veined. Lemma surface scaberulous; rough above and in lines. Lemma margins convolute; covering most of palea. Lemma apex awned; 3 -awned. Principal lemma awn 3-branched; spreading; with 35–45 mm long limb; without a column. Lateral lemma awns 35–45 mm long; subequal to principal.

FLOWER Anthers 3.

DISTRIBUTION North America: western Canada, northwest USA, north-central USA, southwest USA, south-central USA, southeast USA, and Mexico. South America: Caribbean.

NOTES Aristideae. Gr Tex 1993.

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