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 subspicata

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 20–50 cm long; 2–3 -noded. Culm-internodes terete; smooth, or scaberulous. Lateral branches lacking, or sparse. Leaf-sheaths mostly shorter than adjacent culm internode; keeled; scaberulous; glabrous on surface. Leaf-sheath oral hairs ciliate. Ligule a fringe of hairs. Collar glabrous. Leaf-blades filiform, or linear; flat, or convolute; 5–20 cm long; 0.5–3 mm wide. Leaf-blade midrib keeled beneath. Leaf-blade venation distinct. Leaf-blade surface scabrous; rough adaxially. Leaf-blade margins scabrous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle; exserted, or embraced at base by subtending leaf. Peduncle pubescent above to hirsute above.

Panicle spiciform; linear, or oblong; 6–15 cm long. Primary panicle branches 1 -nate. Panicle axis terete, or angular; scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 6–7 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.5 mm long; pilose; obtuse.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 4–7 mm long; membranous; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume surface glabrous, or hispidulous. Lower glume apex acuminate; awned; 1 -awned. Lower glume awn 1–3 mm long. Upper glume lanceolate; 6–7 mm long; membranous; 1-keeled; 1 -veined. Upper glume primary vein scaberulous. Upper glume lateral veins absent. Upper glume apex dentate; 2 -fid; awned; 1 -awned. Upper glume awn 2–3 mm long.

FLORETS Fertile lemma oblong; subterete; 3–4 mm long; coriaceous; keeled; lightly keeled; 3 -veined. Lemma surface smooth, or papillose; rough above. Lemma margins convolute; covering most of palea. Lemma apex acute; awned; 3 -awned. Principal lemma awn 3-branched; with 10–15 mm long limb; with twisted column; deciduous; abscissing from top of column. Column of lemma awn 1.5–4 mm long. Lateral lemma awns 12–15 mm long; subequal to principal.

DISTRIBUTION South America: western South America.

NOTES Aristideae. Henrard 1999.

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