Echinochlo inundata Michael & Vickery. Telopea 1: 46 (1975).
Classification. (GPWG 2001) : Subfamily Panicoideae. Paniceae.
Type of Basionym or Protologue Information: Australia: New South Wales: Western Plains, Boorooma Creek, between Walgett and Brewarrina, 27 Feb 1968, P. Michael A 80 (HT: NSW-113971).
Key references (books and floras): [1981] M.Lazarides in J.Jessop (ed)., Flora of Central Australia (477), [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia, [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia (449), [2008] S.W.L.Jacobs, R.D.B.Walley & D.J.B.Wheeler, Grasses of New South Wales (227).
Illustrations: [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia (448, Fig. 380), [2008] S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th edn (227).
Habit. Annual. Rhizomes absent. Stolons absent. Culms erect or geniculately ascending, 30–150 cm tall, 4–8 mm diam., compressible, 4–6 -noded. Mid-culm nodes glabrous. Lateral branches simple. Leaf-sheaths glabrous on surface. Ligule absent. Leaf-blades 10–40 cm long, 6–15 mm wide. Leaf-blade surface smooth, glabrous.
Inflorescence. Inflorescence compound, a panicle of racemes. Racemes numerous, erect or ascending, 2–6 cm long. Central inflorescence axis 15–25 cm long.
Spikelets. Spikelets pedicelled. Fertile spikelets 2-flowered, the lower floret barren (rarely male), the upper fertile, comprising 1 basal sterile florets, comprising 1 fertile floret(s), without rachilla extension, elliptic, dorsally compressed, 3.4–5 mm long. Rhachilla internodes elongated between glumes.
Glumes. Glumes dissimilar, thinner than fertile lemma. Lower glume ovate, membranous, without keels, 3–5 -nerved. Lower glume apex mucronate or awned. Upper glume ovate, 3.3–4.8 mm long, membranous, without keels, 5–7 -nerved. Upper glume surface scabrous, indumented. Upper glume apex muticous or mucronate or awned. Florets. Basal sterile florets 1, male or barren, with palea. Lemma of lower sterile floret 100 % of length of spikelet, membranous, 5–7 -nerved, muticous or awned.
Fertile lemma 3.1–3.8 mm long, without keel, 5 -nerved. Lemma apex mucronate. Anthers 3. Grain 1.8–2.2 mm long.
Continental Distribution: Australasia.
Australian Distribution: South Australia, Queensland, New South Wales.
South Australia: Lake Eyre, Gairdner-Torrens Basin. Queensland: Burnett, Cook, Darling Downs, Leichhardt, Port Curtis, Wide Bay, South Kennedy, Mitchell. New South Wales: North-Western Plains, South-Western Plains, North Far Western Plains.
Notes. Morphologically similar to E. turneriana. It differs in lacking a ligule, the spikelets are typically larger and the lower lemma typically has a pronounced awn.
Native. The distribution of E. inundata is S of E. turneriana. In Brigalow forests, semi-arid shrub woodlands, shrub steppe shrublands, acacia shrublands, arid tussock grasslands, and arid hummock grasslands. Flowers Feb.-July.
