Aristida uruguayensis

HABIT Perennial. Culms 27–50(–73) cm long. Lateral branches lacking. Leaf-sheath oral hairs lacking. Ligule a fringe of hairs; 0.2 mm long. Collar glabrous. Leaf-blades curved; conduplicate; 15–35 cm long, or 0 cm long; 1.8 mm wide, or 0.2–3.2 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous. Leaf-blade apex acute; antrorsely scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; 15–24(–28) 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; 0.7–0.8 mm long; pilose; acute (subacute).

GLUMES Glumes persistent; dissimilar (lower shorter than upper). Lower glume lanceolate; (13–)17–21 mm long; 1(–3) -veined (lateral veins free). Lower glume primary vein scabrous. Lower glume surface asperulous; rough generally. Lower glume apex setaceously attenuate. Upper glume lanceolate; 27–37(–40) mm long; 1 -veined. Upper glume surface smooth. Upper glume apex entire; acuminate.

FLORETS Fertile lemma laterally compressed; 13–18 mm long; keeled; distinctly keeled; keeled above; 3 -veined. Lemma midvein without distinctive roughness, or scabrous. Lemma surface smooth; without grooves. Lemma margins convolute. Lemma apex awned; 3 -awned. Principal lemma awn straight; ascending; simple at base; with 75–130 mm long limb; without a column. Lateral lemma awns ascending; 75–130 mm long; subequal to principal.

DISTRIBUTION South America: Brazil and southern South America.

NOTES Aristideae. LO-W 1993.

ADDITIONAL CHARACTERS Culms grouped in fascicles. Lemma apex with an hyaline appendage 1–1.5mm.

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