GrassBase - The Online World Grass Flora


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

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

Aristida torta

HABIT Perennial. Culms 42–90 cm long. Lateral branches lacking. Leaf-sheath oral hairs scanty, or bearded (deciduous hairs). Ligule a ciliolate membrane; 0.2 mm long. Collar glabrous. Leaf-blades straight; conduplicate; 8.5 cm long, or 2–40 cm long; 1.5–4 mm wide. Leaf-blade surface scabrous; rough adaxially; glabrous, or pilose; sparsely hairy; hairy adaxially (at margins). Leaf-blade apex obtuse; smooth.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted (or subcontracted); 9–30 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 mm long; pilose; obtuse.

GLUMES Glumes persistent; dissimilar (lower generally shorter than upper, sometimes subequal or lower longer than upper). Lower glume lanceolate; 7.5–9 mm long; 1 -veined. Lower glume primary vein scabrous. Lower glume surface scabrous; rough on veins. Lower glume apex acute; muticous, or awned (shortly). Upper glume lanceolate; 4.5–8 mm long; 1 -veined. Upper glume surface smooth. Upper glume apex entire; acute; muticous, or awned (shortly).

FLORETS Fertile lemma subterete; 3.5–5 mm long; without keel; rounded throughout; 3 -veined. Lemma surface scabrous; rough above; without grooves. Lemma margins convolute. Lemma apex awned; 3 -awned. Principal lemma awn curved; recurved at base of limb (generally); simple at base; with 7–17 mm long limb; without a column. Lateral lemma awns ascending; 5–11.5 mm long (1/3–2/3 the lenght of the principal awn); shorter than principal (conspicuously).

DISTRIBUTION South America: Mesoamericana, northern South America, western South America, and Brazil.

NOTES Aristideae. LO-W 1993.

ADDITIONAL CHARACTERS Blades constricted near the apex.

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