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Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Setaria reverchonii

HABIT Perennial; caespitose. Butt sheaths pilose, or villous. Culms 35–70 cm long. Ligule a fringe of hairs; 1–2 mm long. Leaf-blades flat, or involute; 6–20 cm long; 1.5–3 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 6–20; borne along a central axis; paucilateral; 0.5–1.5 cm long; bearing few fertile spikelets; bearing 1–10 fertile spikelets on each. Central inflorescence axis 6–20 cm long; tip with blunt extension. Rhachis subterete; scabrous on surface; terminating in a barren extension; extension bristle-like; extension 2–6 mm long. Spikelet packing abaxial; lax; irregular.

Spikelets solitary, or in pairs. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; subacute; (2.5–)3–4 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; clasping; 0.33–0.5 length of spikelet; membranous; without keels; 5 -veined. Lower glume apex obtuse. Upper glume elliptic; 1 length of spikelet; membranous; without keels; 9 -veined. Upper glume apex obtuse.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 5 -veined; obtuse, or acute. Fertile lemma elliptic; 2–3.5 mm long; indurate; without keel. Lemma surface rugulose. Lemma margins involute. Lemma apex acute. Palea reflexed at apex; indurate. Palea surface rugose.

DISTRIBUTION North America: south-central USA and Mexico.

NOTES Paniceae. Gould.

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