Aristida capillacea

HABIT Annual. Culms 11–24 cm long. Leaf-sheath oral hairs scanty, or bearded (sparsely). Ligule a ciliolate membrane; 0.2 mm long. Collar glabrous. Leaf-blades straight; conduplicate; 2.1–6 cm long; 0.8–0.9 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous, or pilose; sparsely hairy; hairy adaxially. Leaf-blade apex acute; antrorsely scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open (capilaceous branches); 6–10 cm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets subterete; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.2 mm long; pilose; obtuse.

GLUMES Glumes dissimilar (lower shorter than upper). Lower glume lanceolate; 2.5–3.5 mm long; 1 -veined. Lower glume primary vein scabrous. Lower glume surface scabrous; rough generally. Lower glume apex acute, or acuminate; muticous. Upper glume lanceolate; 3.2–3.9 mm long; 1 -veined. Upper glume surface smooth. Upper glume apex entire; acute, or acuminate.

FLORETS Fertile lemma subterete; 2–3.6 mm long; without keel; rounded throughout; 3 -veined. Lemma surface scaberulous; rough above; without grooves. Lemma margins convolute. Lemma apex awned; 3 -awned. Principal lemma awn straight; ascending; simple at base; with 7–8 mm long limb; with twisted column. Column of lemma awn 1–2 mm long. Lateral lemma awns ascending; 6–7 mm long; subequal to principal.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, northern South America, western South America, and Brazil.

NOTES Aristideae. LO-W 1993.

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