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.

Setaria welwitschii

HABIT Perennial. Rhizomes short. Culms erect, or geniculately ascending; 200–300 cm long; 4 mm diam. Culm-internodes 7–10 cm long. Lateral branches ample. Leaf-sheaths tight; mostly shorter than adjacent culm internode; keeled; smooth; glabrous on surface, or pilose; outer margin hairy. Ligule a fringe of hairs. Leaf-blades 5–30 cm long; 3–7 mm wide; stiff, or firm. Leaf-blade midrib prominent beneath. Leaf-blade venation with 6–8 secondary veins. Leaf-blade surface scabrous; rough adaxially; glabrous, or pilose; sparsely hairy. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle. Peduncle 20–25 cm long; antrorsely scabrous above; hirsute above.

Panicle contracted, or spiciform; oblong, or pyramidal; continuous, or interrupted; 2.5–13 cm long; 0.4–2.4 cm wide. Primary panicle branches 0.1–1.6 cm long; bearing spikelets almost to the base; sterile at the tips. Panicle axis angular; villous. Panicle branches puberulous.

Spikelets subtended by an involucre. Fertile spikelets sessile; 3–5 in the cluster. Involucre composed of bristles; 7–9 mm long. Involucral bristles persistent; 3–5 in principal whorl; with one conspicuously longer bristle; 12–16 mm long; antrorsely scaberulous; glabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; gibbous; 2–2.5 mm long; 1 mm wide; falling entire.

GLUMES Glumes reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.33–0.5 length of spikelet; membranous; without keels; 3 -veined. Lower glume apex acute. Upper glume ovate; 1 length of spikelet; membranous; without keels; 5–7 -veined. Upper glume primary vein depressed. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret ovate; 1 length of spikelet; membranous; 5–7 -veined; flat across back; acute. Fertile lemma ovate; dorsally compressed; gibbous; 2–2.5 mm long; indurate; pallid; without keel. Lemma surface smooth, or granulose. Lemma margins involute. Lemma apex acute. Palea involute; indurate.

DISTRIBUTION Africa: southern tropical and middle Atlantic ocean.

NOTES Paniceae. FTA 1997.

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