Aristida geminiflora

HABIT Perennial. Culms erect; 50–60 cm long. Leaf-sheaths scaberulous; glabrous on surface. Leaf-sheath oral hairs lacking. Ligule a fringe of hairs. Leaf-blades involute; 5–10 cm long; 1–2 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; loose; 10–15 cm long. Primary panicle branches ascending; 1 -nate; 3 cm long; bearing 4–6 fertile spikelets on each lower branch.

Spikelets solitary.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 12 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; pubescent; obtuse.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 12 mm long; 1.1 length of upper glume; membranous; 1 -veined. Lower glume lateral veins absent. Upper glume lanceolate; 11 mm long; 1.4 length of adjacent fertile lemma; membranous; 1 -veined. Upper glume lateral veins absent.

FLORETS Fertile lemma linear; subterete; 8 mm long; coriaceous; without keel; 3 -veined. Lemma surface glabrous. Lemma margins convolute; covering most of palea. Lemma apex awned; 3 -awned. Principal lemma awn 3-branched; recurved at base of limb; with 8 mm long limb; with twisted column. Column of lemma awn 6 mm long. Lateral lemma awns 1 mm long; shorter than principal.

FLOWER Anthers 3.

DISTRIBUTION North America: Mexico.

NOTES Aristideae. Hitchcock 2001.

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