Setaria viridis

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 10–60 cm long; 3–5 -noded. Culm-nodes glabrous. Leaf-sheaths outer margin hairy. Ligule a fringe of hairs. Leaf-blades 3–30 cm long; 4–10 mm wide. Leaf-blade surface scaberulous; glabrous.

INFLORESCENCE Inflorescence a panicle. Peduncle scaberulous above.

Panicle spiciform; linear; 1–10 cm long; 0.4–1 cm wide. Primary panicle branches accrescent to a central axis; with evident branchlets on axis. Panicle axis hispid, or pilose.

Spikelets subtended by an involucre. Fertile spikelets pedicelled; 2–6 in the cluster. Involucre composed of bristles; free throughout; 5–10 mm long. Involucral bristles persistent; few; in one whorl; 4–14 in principal whorl; 1–3 per spikelet; flexible; antrorsely scaberulous; glabrous. Pedicels oblong.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; obtuse; 2–3 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume oblate; 0.25–0.33 length of spikelet; membranous; without keels; 1–3 -veined. Lower glume apex obtuse. Upper glume elliptic; 1 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex obtuse.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret similar to upper glume; oblong; 1 length of spikelet; membranous; 5–7 -veined; obtuse. Palea of lower sterile floret membranous (0.33–0.5 length of lemma). Fertile lemma elliptic; dorsally compressed; 2–3 mm long; indurate; without keel. Lemma surface rugulose. Lemma margins involute. Lemma apex obtuse. Palea involute; indurate.

FLOWER Anthers 3; 0.8 mm long.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Africa: north, Macaronesia, and northeast tropical. Asia-temperate: Siberia, Soviet far east, Soviet Middle Asia, Caucasus, western Asia, Arabia, China, Mongolia, and eastern Asia. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia and New Zealand. North America: Subarctic, western Canada, eastern Canada, northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, southeast USA, and Mexico. South America: Mesoamericana, Caribbean, Brazil, and southern South America.

NOTES Paniceae. CEH.

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