Setaria magna

HABIT Annual. Culms erect, or geniculately ascending; robust; 200–400 cm long; 10–20 mm diam. Culm-nodes glabrous. Leaf-sheaths smooth, or scaberulous; outer margin hairy. Ligule a fringe of hairs; 1–2 mm long. Leaf-blades 30–60 cm long; 20–35 mm wide. Leaf-blade surface scabrous. Leaf-blade margins cartilaginous; scabrous.

INFLORESCENCE Inflorescence a panicle. Peduncle scaberulous above.

Panicle spiciform; linear; dense; 20–45 cm long; 1.5–3 cm wide. Primary panicle branches 0.5–1.5 cm long; sterile at the tips. Panicle axis angular; scabrous; villous.

Spikelets subtended by an involucre. Fertile spikelets pedicelled; 1 in the cluster. Involucre composed of bristles; 10–20 mm long. Involucral bristles persistent; 1–2 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 mm long; falling entire; readily shedding fertile florets.

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

FLORETS Basal sterile florets male, or barren; with palea. Lemma of lower sterile floret ovate; 1 length of spikelet; membranous; 5–7 -veined; acute. Palea of lower sterile floret 1 length of lemma. Fertile lemma ovate; dorsally compressed; gibbous; 1.8 mm long; indurate; light brown; shiny; without keel. Lemma surface smooth. Lemma margins involute. Palea involute; indurate.

DISTRIBUTION North America: northeast USA, south-central USA, southeast USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Paniceae. Rominger 1994.

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