GrassBase - The Online World Grass Flora


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

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

Setaria australiensis

HABIT Perennial; caespitose. Rhizomes short. Culms 100–210 cm long; 3–6 mm diam.; 6 -noded. Culm-internodes elliptical in section. Culm-nodes black; glabrous. Lateral branches lacking, or sparse. Leaf-sheaths keeled; outer margin glabrous, or hairy. Ligule a fringe of hairs; 2–3 mm long. Leaf-blades lanceolate; flat, or plicate; 15–30 cm long; 5–20 mm wide. Leaf-blade midrib prominent beneath. Leaf-blade surface scaberulous. Leaf-blade margins cartilaginous; scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle. Peduncle antrorsely scabrous above.

Panicle contracted; linear, or lanceolate; 6–20 cm long; 1.5–2 cm wide. Primary panicle branches appressed, or ascending; 1–2.2 cm long; sterile at the tips. Panicle axis pubescent and pilose. Panicle branches scabrous; glabrous, or pubescent.

Spikelets subtended by an involucre. Fertile spikelets pedicelled; 1 in the cluster. Involucre composed of bristles. Involucral bristles persistent; 1–3 per spikelet; 8–20 mm long; antrorsely scaberulous; glabrous. Pedicels reduced to a stump; tip cupuliform.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic, or ovate; dorsally compressed; gibbous; acute; 3–4 mm long; falling entire.

GLUMES Glumes shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.33–0.5 length of spikelet; membranous; without keels; 3–5 -veined. Lower glume apex acute. Upper glume ovate; 0.75–0.9 length of spikelet; membranous; without keels; 7–11 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret elliptic; 1 length of spikelet; membranous; 5–7 -veined; acute. Fertile lemma ovate; dorsally compressed; gibbous; 3–4 mm long; indurate; without keel. Lemma surface rugose. Lemma margins involute. Lemma apex acute. Palea involute; indurate. Palea surface rugose.

FLOWER Anthers 3; 1–1.5 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 2.25 mm long. Embryo 0.5 length of caryopsis. Hilum punctiform.

DISTRIBUTION Australasia: Australia.

NOTES Paniceae. Vickery 1993.

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