GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Aristida oligospira

HABIT Perennial. Culms 70–110(–140) cm long. Lateral branches lacking. Leaf-sheath oral hairs bearded. Ligule a fringe of hairs, or a ciliolate membrane (rarely); 0.2 mm long. Collar glabrous. Leaf-blades straight; conduplicate; 30–80 cm long; 3–4 mm wide. Leaf-blade surface scabrous (densely); rough adaxially; glabrous. Leaf-blade apex acute; antrorsely scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; (13–)15–27 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; straight; 0.2–0.3 mm long; pilose; obtuse.

GLUMES Glumes persistent; dissimilar (lower longer than upper sometimes subequal). Lower glume lanceolate; 12–15 mm long; 1 -veined. Lower glume primary vein scabrous. Lower glume surface asperulous; rough generally. Lower glume apex setaceously attenuate. Upper glume lanceolate; 11–13 mm long; 1 -veined. Upper glume surface smooth. Upper glume apex entire; setaceously attenuate.

FLORETS Fertile lemma subterete; 6–7 mm long; without keel; rounded throughout; 3 -veined. Lemma surface papillose; rough above; with a median groove (ventral,longitudinal). Lemma margins involute. Lemma apex awned; 3 -awned. Principal lemma awn flexuous; reflexed, or twisted together; simple at base; with 22–32 mm long limb; with twisted column. Column of lemma awn 7–12 mm long. Lateral lemma awns wrapped around principal (or reflexed); 19–27 mm long; shorter than principal.

DISTRIBUTION South America: Brazil and southern South America.

NOTES Aristideae. LO-W 1993.

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