Bromus diandrus* Roth. Symb. Bot. 2: 22 (1791).
Classification. (GPWG 2001) : Subfamily Pooideae. Tribe Bromeae.
Type of Basionym or Protologue Information: NT: Gr. Bromoides, locustis maximus, lanuginosum, Italicum. Hist. Nat.: 261, no. 444, (OXF (Scheuzer Herb.)). NT designated by Sales, Edinb. J. Bot. 50(1): 8 (1993).
Key references (books and floras): [1952] C.A.Gardner, Flora of Western Australia 1 Gramineae (98 as Bromus gussonii), [1981] M.Lazarides in J.Jessop (ed)., Flora of Central Australia (432), [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia, [2002] J.Wheeler, N.Marchant & M.Lewington, Flora of the South West (407), [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia (256), [2008] S.W.L.Jacobs, R.D.B.Walley & D.J.B.Wheeler, Grasses of New South Wales (175), [2009] A.Wilson (ed.). Flora of Australia, Vol 44A. Poaceae 2 (86).
Illustrations: [1952] C.A.Gardner, Flora of Western Australia 1 Gramineae (97, Pl.27 as B. gussonii), [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia (257, Fig. 198), [2008] S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th edn (175).
Habit. Annual. Culms erect or geniculately ascending, 35–150 cm tall, 3–6 -noded. Leaf-sheaths hairy. Ligule an eciliate membrane, 3–6 mm long, lacerate. Leaf-blades 4–25 cm long, 2–8 mm wide. Leaf-blade surface scaberulous, indumented.
Inflorescence. Inflorescence compound, a panicle. Panicle ovate, effuse, 6.5–25 cm long.
Spikelets. Spikelets pedicelled. Fertile spikelets many flowered, with at least 2 fertile florets (5–8), comprising 5–8 fertile floret(s), with diminished florets at the apex, obovate or cuneate, laterally compressed, (20–)27–60 mm long.
Glumes. Glumes dissimilar. Lower glume linear, chartaceous, without keels or keeled, 1-keeled, 1–3 -nerved. Upper glume lanceolate, 20–45 mm long, chartaceous, without keels or keeled, 1-keeled, 3(–5) -nerved.
Florets. Fertile lemma 17–45 mm long, without keel or keeled, 7 -nerved. Lemma apex dentate, awned, 1 -awned. Median (principal) awn apical or subapical, 35–75 mm long overall. Lodicules present. Anthers 2–3.
Continental Distribution: Europe, Africa, Temperate Asia, Tropical Asia, Australasia, Pacific, North America, and South America.
Australian Distribution: Western Australia, Northern Territory, South Australia, Queensland, New South Wales, Victoria, Tasmania, Norfolk I, Lord Howe.
Western Australia: Carnarvon. Irwin, Drummond, Dale, Menzies, Avon. Northern Territory: Central Australia South. South Australia: Lake Eyre, Nullabor, Gairdner-Torrens Basin, Flinders Ranges, Eyre Peninsula, Northern Lofty, Murray, Yorke Peninsula, Southern Lofty, Kangaroo Island, South-eastern. Queensland: Burnett, Darling Downs, Moreton. New South Wales: North Coast, Central Coast, South Coast, Northern Tablelands, Central Tablelands, Southern Tablelands, North-Western Slopes, Central-Western Slopes, South-Western Slopes, North-Western Plains, South-Western Plains, South Far Western Plains. Victoria: East Gippsland, Eastern Highlands, Gippsland Highlands, Gippsland Plain, Grampians, Lowan Mallee, Midlands, Murray Mallee, Otway Plain, Otway Range, Wilsons Promontory, Riverina, Volcanic Plain, Wannon, Wimmera. Tasmania: Furneaux Group, North West, Midlands, East Coast, South West.
Notes. Introduced. Tas., N.S.W., A.C.T., Vic., W.A. and S.A., also Lord Howe Is. Native of the Mediterranean and western Asia, widely naturalized. Widespread, a weed of disturbed sites and crops. Flowers Sept.-Dec.
