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.

Setaria villosissima

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 4–10 cm long. Culm-internodes elliptical in section; distally glabrous. Culm-nodes glabrous, or pubescent. Leaf-sheaths antrorsely scabrous; hirsute; outer margin hairy. Leaf-sheath oral hairs bearded. Ligule a fringe of hairs; 1 mm long. Leaf-blades linear, or lanceolate; 15–30 cm long; 6–8 mm wide. Leaf-blade midrib prominent beneath. Leaf-blade surface pubescent; hairy on both sides. Leaf-blade margins cartilaginous; scabrous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; lanceolate; loose; 20 cm long; 2–3 cm wide. Primary panicle branches ascending; 2–3 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; 15–25 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 ovate; dorsally compressed; 2.5–3 mm long; falling entire.

GLUMES Glumes reaching apex of florets; thinner than fertile lemma. Lower glume ovate; clasping; 0.33 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 apex acute; mucronate.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret ovate; 1 length of spikelet; membranous; 5 -veined; sulcate; acuminate. Palea of lower sterile floret 0.2 length of lemma. Fertile lemma ovate; dorsally compressed; gibbous; 2.5–3 mm long; indurate; without keel. Lemma surface rugulose. Lemma margins involute. Lemma apex apiculate. Palea involute; indurate.

DISTRIBUTION North America: southwest USA and south-central USA.

NOTES Paniceae. Rominger 1994.

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