Aristida hamulosa

HABIT Perennial; caespitose. Culms 30–75 cm long. Leaf-sheath oral hairs ciliate. Ligule a fringe of hairs; 0.5 mm long. Leaf-blades involute; 10–30 cm long; 1–3 mm wide. Leaf-blade surface scabrous; glabrous; hairless throughout, or except near base.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 10–40 cm long; with spikelets clustered towards branch tips. Primary panicle branches spreading, or reflexed; 8–15 cm long.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 9–15 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.5 mm long; pubescent; obtuse.

GLUMES Glumes similar; reaching apex of florets; thinner than fertile lemma. Lower glume lanceolate; 9–15 mm long; 1–1.1 length of upper glume; membranous; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 9–15 mm long; 1 length of adjacent fertile lemma; membranous; 1 -veined. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma linear; subterete; 10–15 mm long; coriaceous; without keel; 3 -veined. Lemma surface scabrous. Lemma margins convolute; covering most of palea. Lemma apex awned; 3 -awned. Principal lemma awn 3-branched; ascending; with 8–25 mm long limb; with a straight or slightly twisted column. Column of lemma awn 2–3 mm long. Lateral lemma awns spreading less than principal; 8–25 mm long; subequal to principal, or shorter than principal.

FLOWER Anthers 3.

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

NOTES Aristideae. Gr Tex 1993.

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