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.

Alloteropsis semialata

HABIT Perennial; caespitose. Rhizomes short; woody. Butt sheaths thickened and forming a bulb (base at times flabellate); pubescent, or woolly. Culms erect, or geniculately ascending; 20–150 cm long. Culm-internodes eglandular; ridged; smooth; distally glabrous. Culm-nodes bearded. Lateral branches lacking. Leaves basal and cauline. Leaf-sheaths loose; open for most of their length; with flat margins; 2–15 cm long; longer than adjacent culm internode; wider than blade at the collar; without keel; striately veined; glabrous on surface, or woolly; with simple hairs, or tubercle-based hairs; outer margin hairy. Leaf-sheath oral hairs bearded. Ligule a ciliate membrane (ca 0.75mm), or a fringe of hairs. Collar glabrous, or pubescent. Leaf-blade base tapering to the midrib, or simple (rarely). Leaf-blades flat, or convolute; 10–50 cm long; 1–10 mm wide; light green, or glaucous. Leaf-blade midrib evident; prominent beneath. Leaf-blade venation distinct. Leaf-blade surface scabrous; rough on both sides; glabrous, or hirsute; hairy on both sides; with tubercle-based hairs. Leaf-blade margins glabrous, or tuberculate-ciliate. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–4(–8); digitate; unilateral; 2–22 cm long. Rhachis angular; with scattered hairs (rarely), or villous on surface. Spikelet packing irregular.

Spikelets solitary (rarely), or in pairs, or clustered at each node. Fertile spikelets pedicelled; 2–4 in the cluster. Pedicels angular; ciliate, or villous; hairy all along but hairs longer above; tip cupuliform.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension, or with a barren rhachilla extension. Spikelets ovate; dorsally compressed; 4–7.5 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.5–0.7 length of spikelet; membranous; without keels; 3 -veined. Lower glume apex acuminate. Upper glume ovate; 1 length of spikelet; membranous; light green (rarely with transverse purple bands); without keels; 5 -veined. Upper glume surface puberulous. Upper glume margins ciliate. Upper glume apex acuminate.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret ovate; 1 length of spikelet; chartaceous; fenestrate (at base); 5 -veined; truncate. Fertile lemma lanceolate; 3.5–7 mm long; chartaceous; dark brown; without keel; 5 -veined. Lemma margins involute; ciliolate. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn 1.5–3 mm long overall. Palea chartaceous. Palea surface smooth; pubescent. Rhachilla extension 0–0.1 length of fertile floret.

FLOWER Lodicules 2; cuneate. Anthers 2, or 3; 0.3 mm long; brown. Stigmas yellow, or purple. Styles 0.3 mm long. Ovary glabrous.

FRUIT Caryopsis ovoid; 1.3–1.5 mm long. Disseminule comprising a spikelet.

DISTRIBUTION Africa: west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, and western Indian ocean. Asia-temperate: China and eastern Asia. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia. Pacific: southwestern.

NOTES Paniceae. VJN.

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