Aristida chapadensis

HABIT Perennial. Culms 90–106 cm long. Lateral branches lacking. Leaf-sheath oral hairs scanty, or bearded (sparsely). Ligule a ciliolate membrane; 0.2 mm long. Collar glabrous. Leaf-blades straight; flat, or convolute (sometimes upper); 20–50(–60) cm long; 4–7 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous. Leaf-blade apex acute; antrorsely scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; 30–40 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; 1.5–1.8 mm long; bearded; acute.

GLUMES Glumes persistent; dissimilar (lower longer than upper). Lower glume lanceolate; (16–)17–19(–22) mm long; 1 -veined. Lower glume primary vein scaberulous. Lower glume surface asperulous; rough generally. Lower glume apex setaceously attenuate. Upper glume lanceolate; 14–16(–19) mm long; 1 -veined. Upper glume surface smooth. Upper glume apex entire; setaceously attenuate.

FLORETS Fertile lemma subterete; 8–10 mm long; without keel; rounded throughout; 3 -veined. Lemma surface scaberulous; 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 (35–)45–56 mm long limb; with twisted column. Column of lemma awn (13–)16–25 mm long. Lateral lemma awns ascending; 28–46 mm long; shorter than principal.

DISTRIBUTION South America: Brazil.

NOTES Aristideae. LO-W 1993.

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