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.

Sehima nervosum

HABIT Perennial; caespitose. Culms erect; 30–100 cm long; wiry. Ligule a fringe of hairs. Leaf-blades 5–40 cm long; 2–7 mm wide; glaucous. Leaf-blade apex attenuate; filiform.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; straight, or arcuate; 3–12 cm long. Rhachis fragile at the nodes; flattened; ciliate on margins. Rhachis internodes cuneate. Rhachis internode tip oblique; crateriform.

Spikelets squeezed between internode and pedicel; in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels cuneate; flattened; ciliate; tip rectangular.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; dorsally compressed; 6–10 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes coriaceous; distinctly veined; 5–7 -veined; ciliate on margins; acute; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 6–10 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus square; pilose; base obtuse; inserted.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume elliptic; asymmetrical; 1 length of spikelet; coriaceous; much thinner above; 2-keeled; keeled dorsally below, flaring to lateral above; winged on keel; winged narrowly; winged near apex. Lower glume lateral veins branching above; intercarinal veins absent below, prominent above. Lower glume surface deeply depressed. Lower glume apex dentate; 2 -fid; mucronate. Upper glume elliptic; chartaceous; 1-keeled; 5 -veined. Upper glume margins ciliate. Upper glume apex acute; awned; 1 -awned. Upper glume awn 14–16 mm long.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret oblong; 6 mm long; hyaline; 2 -veined; ciliate on margins. Fertile lemma lanceolate; 5 mm long; hyaline; without keel; 3 -veined. Lemma margins ciliate. Lemma apex lobed; 2 -fid; incised 0.3 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 20–40 mm long overall; with twisted column. Column of lemma awn hispidulous; hairy on the spiral. Palea 1 length of lemma; hyaline; without keels.

DISTRIBUTION Africa: northeast tropical, east tropical, and southern tropical. Asia-temperate: Arabia and China. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia.

NOTES Andropogoneae. FTEA.

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