Setaria johnsonii

HABIT Annual. Culms erect, or decumbent; 7–20 cm long; 3–5 -noded. Leaf-sheaths outer margin glabrous. Ligule a fringe of hairs. Leaf-blades involute; 1–4 cm long; 5–7 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 10–20; single (apparently, when racemes reduced to 1 spikelet), or borne along a central axis; appressed; unilateral; 0.4–0.6 cm long; bearing few fertile spikelets; bearing 1(–2) fertile spikelets on each. Central inflorescence axis 1.5–4 cm long. Rhachis narrowly winged; angular; terminating in a barren extension; extension subulate; extension 0.7–0.8 mm long. Spikelet packing abaxial.

Spikelets solitary, or subtended by an involucre (actually the extension of a 1-spikelet raceme). Fertile spikelets sessile. Involucre composed of bristles; 0.7–0.8 mm long. Involucral bristles 1 per spikelet.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; plano-convex; 2.1–2.5 mm long; 0.9–1 mm wide; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 1.5 mm long; 0.75 length of spikelet; membranous; without keels; 5 -veined. Lower glume apex truncate. Upper glume elliptic; 2.1–2.5 mm long; 1 length of spikelet; membranous; without keels; 7 -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; acute. Fertile lemma elliptic; 2.1–2.4 mm long; indurate; yellow; without keel. Lemma surface rugose. Lemma margins involute. Lemma apex acute. Palea indurate. Palea surface rugose.

DISTRIBUTION Australasia: Australia.

NOTES Paniceae. Simon 2011.

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