Aristida achalensis

HABIT Annual. Culms 55–70 cm long. Lateral branches lacking. Leaf-sheath oral hairs bearded. Ligule a fringe of hairs; 0.1 mm long. Collar glabrous. Leaf-blades curled (lower), or straight (upper); flat (lower), or conduplicate (upper); 20–25 cm long; 1.5–2.5 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous. Leaf-blade apex acute; smooth.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; 12–16 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–)0.6 mm long; pilose; acute (subacute).

GLUMES Glumes persistent; dissimilar (lower longer than upper, rarely subequal). Lower glume lanceolate; 11–14 mm long; 1 -veined. Lower glume surface asperulous; rough generally. Lower glume apex acuminate (shortly awned); muticous. Upper glume lanceolate; 10.2–12.5 mm long; 1 -veined. Upper glume surface smooth. Upper glume apex entire; acuminate (shortly awned).

FLORETS Fertile lemma subterete; 4–5 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 16–20 mm long limb; with twisted column. Column of lemma awn 2–3.2 mm long. Lateral lemma awns ascending; 14–16.5 mm long; shorter than principal.

DISTRIBUTION South America: southern South America.

NOTES Aristideae. LO-W 1993.

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