Aristida spegazzinii

HABIT Annual. Culms 22–70 cm long. Lateral branches lacking. Leaf-sheath oral hairs bearded. Ligule a fringe of hairs; 0.8–1.2 mm long. Collar glabrous. Leaf-blades curled, or flexuous; convolute; 5–27 cm long; 0.5–1.2 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous. Leaf-blade apex acute; smooth.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted (subcontracted); 10–15 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; 0.5–1 mm long; pilose; acute (or subacute).

GLUMES Glumes persistent; dissimilar (lower longer than upper). Lower glume lanceolate; 11–17(–20) mm long; 1–3 -veined (lateral veins free). Lower glume surface scabrous; rough generally. Lower glume apex acute (shortly awned); muticous. Upper glume lanceolate; 8–12 mm long; 1 -veined. Upper glume surface smooth. Upper glume apex entire; acute, or acuminate, or setaceously attenuate.

FLORETS Fertile lemma subterete; 10–14(–16) mm long; without keel; rounded throughout; 3 -veined. Lemma surface scabrous; rough above; with a median groove (ventral,longitudinal). Lemma margins involute. Lemma apex awned; 3 -awned. Principal lemma awn straight; ascending; simple at base; with 30–118 mm long limb; without a column. Lateral lemma awns ascending; 30–118 mm long; subequal to 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.