Tufted annual or perennial, culms ascending or erect, to 100 cm. Leaves smooth to finely scabrous, rarely slightly hairy; blade fiat, to 20 cm long and 6 mm wide; ligule truncate, laciniate, 1–4 mm long. Inflorescence a loosely contracted (rarely widely spreading) panicle, 5–30 cm long. Spikelets 3.2–5 mm long, green or purplish; glumes acute, subequal or the upper longer by up to c. 1 mm, scabrous along the keel, often minutely scabrous along the sides; lemma slightly shorter than to slightly longer than upper glume, acute, coarsely scabrous, awned from just above the middle to just below the apex; awn fine, straight, 0.3–1.5 mm long, not or barely exceeding lemma; callus hairs to c. 1 mm long; rachilla bristle c. 1 mm long, sparsely to rather densely covered with hairs to c. 1 mm long; anthers varying from c. 0.3–2 mm long. Flowers Nov.–Mar.
VRiv, GipP, OtP, CVU, EGL, EGU, WPro, HSF, HNF, OtR, MonT, HFE, VAlp. Also NSW, Tas. Rather common in elevated forests in eastern Victoria (e.g. Murrungower, headwaters of the Brodribb River, Mt Ellery, Mt Elizabeth, Bonang and Gelantipy areas), occasional in the lowlands (e.g. Howe Range, Wingan River, lower Snowy River, Wilsons Promontory) and with isolated occurrences in the north-east (Mt Buffalo, Bogong Village area) and in the Otway Range.
In her revision of the Australian species of Deyeuxia, Vickery (1940) described D. scaberula and D. benthamiana as new and distinguished them on the basis of the former being a slender species having its awn placed just below the apex of the lemma, as opposed to the latter being a robust species with its lemma awned from or slightly above midway. After examining a large number of specimens at MEL (including those identified by Vickery), it has become apparent that the variability in habit and placement of the awn do not permit sensible distinction between the two species. Size of the plants appears to be under environmental control, with, as a general rule, robust plants with large, spreading panicles (formerly referred to D. benthamiana) occurring in well-watered mountain forests and smaller plants with more contracted panicles ('typical' D. scaberula) deriving from drier sites or lowland forests. The name D. scaberula has been preferred for retention as the specimens referred to that species (at least in Victoria) far outnumber those called D. benthamiana in the past.
