Hardy, tufted perennial to 1.5 m tall, erect or spreading, with tuberous roots. Leaf rolled in bud. Ligule membranous, white, 1.5-2.5 mm long, truncate to obtuse, minutely hairy on the back. Leaf blade flat, soft, 0.2-1 cm wide, hairless, ridged on upper surface. Inflorescence erect or nodding, 10-30 cm long. Spikelets 2-4 flowered. Glumes pointed, lower 1-nerved and shorter than the upper ones, which are 3 nerved. Lemmas 5-9 nerved.
A naturalised weed of man-made and natural grasslands, most common as A. elatius subsp. bulbosum (Willd.) Spenner., Bulbous Oatgrass (Onion Twitch). Easily spread by the detached, swollen basal internodes.A troublesome agricultural weed in all states except the NT.
A. elatius subsp. bulbosum 'Variegatum', Variegated Bulbous Oatgrass, is a relatively low growing ornamental plant with leaves having white longitudinal stripes.
Source: (2005). Poaceae. In: . Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.