Eragrostis tenellula (Kunth) Steud. Syn.
Pl. Glum. 1: 279 (1854).
Classification. (GPWG 2001) : Subfamily
Chloridoideae. Cynodonteae.
Basionym and/or
Replacement Name: Poa tenellula
Kunth, Revis. Gramin. 1: 113 (1829).
Type of Basionym or
Protologue Information: Australia: littora novae Hollandiae intra
tropicum,.
Recent synonyms:
E. japonica auct.
Key references
(books and floras): [1878] G.Bentham, Flora Australiensis 7 (623 as Sporobolus
lindleyi), [1952] C.A.Gardner, Flora of Western Australia 1 Gramineae
(115 as E. japonica), [1969] E.E.Henty, Manual Grasses New
Guinea (93 as E. japonica), [1981] M.Lazarides in J.Jessop (ed)., Flora
of Central Australia (459 as E. japonica), [2002] D.Sharp &
B.K.Simon, AusGrass, Grasses of Australia, [2006] J.Jessop,
G.R.M.Dashorst, F.M.James, Grasses of South Australia (383), [2008]
S.W.L.Jacobs, R.D.B.Walley & D.J.B.Wheeler, Grasses of New South Wales
(257).
Illustrations:
[1952] C.A.Gardner, Flora of Western Australia 1 Gramineae (117,
Pl.33 as E. japonica), [2005] K.Mallet (ed.), Flora of Australia 44B:
Poaceae 3 (Fig. 64J), [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses
of South Australia (383, fig. 317),
[2008] S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South
Wales, 4th edn (257).
Habit. Annual.
Culms erect or geniculately ascending or decumbent or prostrate, 6–96 cm tall,
2 -noded. Mid-culm nodes glabrous. Lateral branches simple or sparsely
branched. Leaf-sheaths smooth, glabrous on surface. Ligule an eciliate
membrane, 0.2–0.6 mm long. Leaf-blades straight, flat or involute or convolute,
30 cm long, 2–6 mm wide. Leaf-blade surface smooth, glabrous.
Inflorescence.
Inflorescence compound, a panicle. Panicle lanceolate to ovate, 4–50 cm long,
0.5–12 cm wide, contracted about secondary branches.
Spikelets.
Spikelets pedicelled. Fertile spikelets many flowered, with at least 2 fertile
florets (3–12), comprising 3–12 fertile floret(s), with diminished florets at
the apex, linear or oblong, laterally compressed, 1.5–4.7 mm long.
Glumes. Glumes
similar. Lower glume lanceolate, membranous, keeled, 1-keeled, 1 -nerved. Lower
glume apex muticous. Upper glume lanceolate, 0.5–1.3 mm long, membranous,
keeled, 1-keeled, 1 -nerved. Upper glume apex muticous.
Florets.
Fertile lemma 0.7–1.1 mm long, keeled, 3 -nerved. Lemma apex muticous.
Lodicules present. Anthers 2.
Continental
Distribution: Australasia.
Australian
Distribution: Western Australia, Northern Territory, South Australia,
Queensland, New South Wales, Victoria.
Western Australia: Gardner, Dampier.
Canning, Fortescue, Ashburton, Carnarvon. Northern
Territory: Darwin & Gulf, Victoria River, Barkly Tableland, Central Australia
North, Central Australia South. South Australia: North-western, Lake Eyre,
Eastern, Murray.
Queensland:
Burke, Cook, Gregory North, Leichhardt, Maranoa, Mitchell, North Kennedy, Port
Curtis, South Kennedy, Warrego, Gregory South. New South Wales: North Far Western
Plains. Victoria: Midlands, Murray Mallee, Riverina.
Notes.
Distinguishing characters include ligule membranous; panicle decompound,
occupying 1/2–3/4 of plant; florets loose, falling entire, the apical one in
spikelet vestigial; rachilla fragile, straight, the internodes cupular at apex;
glumes, lemmas and paleas hyaline; palea 3-lobed, the keels relatively short,
mostly smooth and sometimes excurrent; anthers two, minute; caryopsis subulate,
shiny.
Eragrostis tenellula was included in
the Asiatic species, E. japonica, which differs by its ciliate (not
fimbriate) membranous ligule, contracted smaller panicle with shorter branches
mostly in interrupted clusters or whorls, and in the morphology of its spikelet
and caryopsis.
Endemic;
widespread in W.A. in the Pilbara and Kimberley
regions, N.T., Qld and northern S.A.
Also scattered occurrences on the Darling R. near Louth, N.S.W. and on the
Murray R., Vic. Almost always in seasonally flooded sites (often in grassland
plains) and in heavy clay loams, either alluvial or derived from basalt,
laterite, limestone or sandstone.; flowers Jan.-Oct.; fruits Jan.-Oct.
