Aristida tenuifolia

HABIT Perennial; caespitose; clumped densely. Culms erect; 60 cm long; 1 mm diam. Leaf-sheaths without keel; glabrous on surface. Leaf-sheath oral hairs ciliate. Ligule a fringe of hairs. Leaf-blades involute; 10–20 cm long; 1–1.5 mm wide. Leaf-blade surface glabrous; hairless except near base. Leaf-blade margins cartilaginous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 15–20 cm long. Primary panicle branches appressed; 5 cm long. Panicle axis scaberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 10–12 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, or exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 10–12 mm long; 1 length of upper glume; membranous; 3 -veined. Lower glume surface scabrous; rough on veins. Lower glume apex setaceously attenuate. Upper glume lanceolate; 10–11 mm long; membranous; 3 -veined. Upper glume lateral veins obscure. Upper glume surface smooth. Upper glume apex setaceously attenuate.

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

DISTRIBUTION North America: Mexico.

NOTES Aristideae. Hitchcock 2004.

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