Setaria latifolia

HABIT Annual. Culms erect, or geniculately ascending; 30–40 cm long. Culm-internodes antrorsely scabrous. Culm-nodes pubescent. Leaf-sheaths hispid; with tubercle-based hairs; outer margin hairy. Ligule a fringe of hairs. Collar glabrous. Leaf-blade base cordate. Leaf-blades lanceolate; 6–8 cm long; 10–15 mm wide. Leaf-blade surface scabrous; rough on both sides; pubescent; sparsely hairy; hairy on both sides. Leaf-blade margins cartilaginous; entire, or crenate; scabrous. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear; loose; tapering above; 5–10 cm long. Primary panicle branches 0.2–0.5 cm long; sterile at the tips. Panicle axis angular; scabrous; with scattered hairs. Panicle branches scabrous.

Spikelets subtended by an involucre. Fertile spikelets pedicelled; 1 in the cluster. Involucre composed of bristles; 5–18 mm long. Involucral bristles persistent; 1 per spikelet; flexible; antrorsely scaberulous; glabrous. Pedicels oblong.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets obovate; dorsally compressed; compressed slightly; 2 mm long; falling entire.

GLUMES Glumes shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.8 length of spikelet; membranous; without keels; 5 -veined. Lower glume apex acute. Upper glume ovate; 0.66 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret ovate; 1 length of spikelet; membranous; 5 -veined; acute. Palea of lower sterile floret 1 length of lemma. Fertile lemma ovate; dorsally compressed; gibbous; 2 mm long; indurate; without keel. Lemma surface corrugate. Lemma margins involute. Palea involute; indurate.

DISTRIBUTION North America: Mexico.

NOTES Paniceae. Rominger 1994.

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