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 annamensis

HABIT Perennial; caespitose. Culms erect; 50–100 cm long; 1–2 mm diam. Culm-internodes distally glabrous. Culm-nodes glabrous. Lateral branches lacking. Leaf-sheaths longer than adjacent culm internode; smooth; glabrous on surface. Leaf-sheath oral hairs ciliate. Ligule a fringe of hairs. Leaf-blades flat, or convolute; 10–35 cm long; 1–1.5 mm wide. Leaf-blade surface scabrous; rough adaxially. Leaf-blade margins cartilaginous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; effuse; 25–50 cm long; 10–20 cm wide; with spikelets clustered towards branch tips. Primary panicle branches 2–3 -nate. Panicle axis scabrous. Panicle branches flexuous; bearded in axils.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scaberulous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 11.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 1 mm long; pubescent; acute.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 11.5 mm long; 1.1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acuminate; awned; 1 -awned. Lower glume awn 2 mm long. Upper glume lanceolate; 10.5 mm long; 1.2 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex dentate; 2 -fid; awned; 1 -awned. Upper glume awn 2 mm long.

FLORETS Fertile lemma linear, or lanceolate; subterete; 9 mm long; coriaceous; without keel. Lemma surface punctate. Lemma margins convolute; covering most of palea. Lemma apex acute; awned; 3 -awned. Principal lemma awn 3-branched; with 20 mm long limb; without a column, or with a straight or slightly twisted column; persistent. Column of lemma awn 0–1 mm long. Lateral lemma awns 13 mm long; shorter than principal. Palea absent or minute.

FLOWER Anthers 3.

DISTRIBUTION Asia-tropical: Indo-China.

NOTES Aristideae. Henrard 2001.

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