Aristida purpurascens

HABIT Perennial; caespitose. Rootstock evident. Rhizomes short. Culms slender; 30–80 cm long; 1–2 mm diam. Lateral branches sparse. Leaf-sheaths without keel; glabrous on surface, or pubescent. Ligule a fringe of hairs; 0.2–0.3 mm long. Leaf-blades flat, or involute; 15–30 cm long; 1–2.5 mm wide. Leaf-blade surface glabrous; hairless except near base.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 10–35 cm long.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 7–10 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.5 mm long; pubescent; acute.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 7–10 mm long; 1.1–1.4 length of upper glume; membranous; 1 -veined. Lower glume lateral veins absent. Lower glume surface scabrous. Lower glume apex acuminate. Upper glume lanceolate; 6–7 mm long; 1–1.1 length of adjacent fertile lemma; membranous; 1 -veined. Upper glume lateral veins absent. Upper glume surface scabrous. Upper glume apex acuminate.

FLORETS Fertile lemma linear; subterete; 5–7 mm long; coriaceous; purple; without keel; 3 -veined. Lemma margins convolute; covering most of palea. Lemma apex awned; 3 -awned. Principal lemma awn spreading; 15–28 mm long overall; with 15–28 mm long limb; without a column. Lateral lemma awns spreading less than principal; 13–18 mm long; shorter than principal.

FLOWER Anthers 3.

DISTRIBUTION North America: eastern Canada, north-central USA, northeast USA, south-central USA, southeast USA, and Mexico. South America: Mesoamericana and Caribbean.

NOTES Aristideae. Gr Tex 1993.

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