Culms erect, to 160 cm high. Leaves glabrous or sparsely ciliate near base; blade finely scabrous to 45 cm long and 25 mm wide; ligule membranous, to 8 mm long. Inflorescence a loose but rather narrow panicle to 40 cm long. Spikelets rather few per inflorescence, drooping, 3–5-flowered; glumes lanceolate, 30–50 mm long, 9–11-nerved; lemma lanceolate, 23–30 mm long (including apical lobes), bilobed at apex with teeth to 3.5 mm long, the lower two lemmas with silky hairs over the lower two-thirds, upper florets commonly glabrous; awn 60–9070 mm long, inserted below midway on lemma; palea 3–10 mm shorter than lemma. Florets falling united at maturity. Flowers Sep.–Dec.
Very similar to A. ludoviciana (which has been regarded as a subspecies of A. sterilis) but distinguished by the larger spikelets. It tends to flower and fruit later in the year than A. ludoviciana.
Source:
Walsh, N.G. (1994). Poaceae. In: Walsh, N.G.; Entwisle, T.J., Flora of Victoria Vol. 2, Ferns and Allied Plants, Conifers and Monocotyledons, pp. 356–627. Inkata Press, Melbourne.
