Aristida riograndensis

HABIT Perennial. Culms 53–115 cm long. Lateral branches lacking. Leaf-sheath oral hairs bearded. Ligule a fringe of hairs; 0.1–0.2 mm long. Collar pubescent (descontinuous on the mid vein). Leaf-blades straight, or curved (slightly); conduplicate; (4–)11–84 cm long; 1–2 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous. Leaf-blade apex acute; antrorsely scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted (subcontracted, not linear); 16–34 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; 0.7–1.2 mm long; pilose; acute (subacute).

GLUMES Glumes persistent; dissimilar (lower shorter than upper). Lower glume lanceolate; 15–23 mm long; 1 -veined. Lower glume primary vein scabrous. Lower glume surface asperulous; rough generally. Lower glume apex setaceously attenuate. Upper glume lanceolate; 23–35 mm long; 1 -veined. Upper glume primary vein scaberulous. Upper glume surface smooth. Upper glume apex entire; setaceously attenuate; awned.

FLORETS Fertile lemma subterete; 13–22(–25) mm long; without keel; rounded throughout; 3 -veined. Lemma midvein scabrous. Lemma surface smooth, or scaberulous; rough above. Lemma margins convolute. Lemma apex awned; 3 -awned. Principal lemma awn straight; ascending; simple at base; with 50–100 mm long limb; without a column. Lateral lemma awns ascending; 50–100 mm long; subequal to principal.

DISTRIBUTION South America: Brazil.

NOTES Aristideae. LO-W 1993.

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