Aristida divaricata

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 25–70 cm long; wiry. Leaf-sheaths without keel. Leaf-sheath oral hairs pubescent, or ciliate. Ligule a fringe of hairs; 0.5–1 mm long. Leaf-blades conduplicate; 6–20 cm long; 1–3 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous, or pubescent; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong; effuse; 10–30 cm long; 0.5 of culm length. Primary panicle branches spreading. Panicle branches with insignificant pulvini.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 8–13 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.5 mm long; pilose; obtuse.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 8–13 mm long; 1 length of upper glume; membranous; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 8–13 mm long; 1.6–1.8 length of adjacent fertile lemma; membranous; 1 -veined. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma linear; subterete; 5–7 mm long; coriaceous; without keel; 3 -veined. Lemma margins convolute; covering most of palea. Lemma apex awned; 3 -awned. Principal lemma awn 3-branched; with 10–15 mm long limb; with twisted column. Column of lemma awn 2–5 mm long. Lateral lemma awns 10–15 mm long; subequal to principal.

FLOWER Anthers 3.

DISTRIBUTION North America: northwest USA, north-central USA, southwest USA, south-central USA, and Mexico. South America: Mesoamericana and southern South America.

NOTES Aristideae. Gr Tex 1993.

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