Aristida setifolia

HABIT Perennial. Culms 40–100(–150) cm long. Lateral branches sparse; arising from mid culm, or upper culm. Leaf-sheath oral hairs lacking (or pilose, deciduous hairs). Ligule a fringe of hairs; 0.2 mm long. Collar glabrous. Leaf-blades straight; conduplicate, or flat (less frequent); (4–)7–25(–46) cm long; 1–6 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous (generally), or pilose; hairless except near base; hairy adaxially. Leaf-blade apex acute; antrorsely scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted (or subcontracted); 9–16(–32) 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 elongated; straight; 0.8–1 mm long; bearded; acute.

GLUMES Glumes persistent; dissimilar (lower shorter than upper). Lower glume lanceolate; 4.2–7 mm long; 1–3 -veined. Lower glume primary vein scabrous. Lower glume surface scabrous; rough generally. Lower glume apex acute; muticous. Upper glume lanceolate; 5.2–8.5 mm long; 1 -veined. Upper glume surface smooth. Upper glume apex dentate; 2 -fid; acute.

FLORETS Fertile lemma subterete; 4–5 mm long; without keel; rounded throughout; 3 -veined. Lemma midvein scabrous (on keel). Lemma surface scaberulous; without grooves. Lemma margins convolute. Lemma apex awned; 3 -awned. Principal lemma awn straight; ascending (generally), or reflexed (less frequent); with 10–24 mm long limb; with twisted column; deciduous; abscissing from top of column. Column of lemma awn 2–5 mm long. Lateral lemma awns ascending; 4–5 mm long; subequal to principal.

DISTRIBUTION 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.