Eriachne benthamii Hartley. J.
Linn. Soc., Bot. 52: 344 (1942).
Classification. (GPWG 2001) : Subfamily
Micrairoideae. Eriachneae.
Type of Basionym or
Protologue Information: HT: Giles s.n., Australia: Norther
Territory: Central Australia: Charlotte Waters (K; IT: MEL).
Key references
(books and floras): [1952] C.A.Gardner, Flora of Western Australia 1
Gramineae (49), [1981] M.Lazarides in J.Jessop (ed)., Flora of
Central Australia (442), [2002] D.Sharp & B.K.Simon, AusGrass,
Grasses of Australia.
Illustrations:
[2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia (423, fig. 354).
Habit.
Perennial. Culms erect or geniculately ascending, 45–90 cm tall. Mid-culm
internodes pruinose. Mid-culm nodes glabrous or pubescent. Lateral branches
simple or sparsely branched or branched. Ligule a fringe of hairs, 0.5–1 mm
long. Leaf-blades flat or convolute, 9–18 cm long, 2–4.5 mm wide. Leaf-blade
surface smooth, glabrous.
Inflorescence.
Inflorescence compound, a panicle. Panicle oblong, dense or loose, 2.5–17 cm
long, 1–3 cm wide.
Spikelets.
Spikelets pedicelled. Fertile spikelets 2-flowered, both fertile, comprising 2
fertile floret(s), without rachilla extension, ovate, laterally compressed,
6–10 mm long.
Glumes.
Glumes similar, thinner than fertile lemma. Lower glume lanceolate to oblong,
membranous or cartilaginous, much thinner on margins, without keels, 9–11
-nerved. Lower glume surface glabrous. Lower glume apex muticous. Upper glume
lanceolate to oblong, 3.5–9 mm long, membranous or cartilaginous, without
keels, 9–11 -nerved. Upper glume surface smooth or asperulous or scabrous,
glabrous. Upper glume apex muticous.
Florets.
Fertile lemma 6–10 mm long, without keel, 5–7 -nerved. Lemma surface
indumented. Lemma apex mucronate or awned, 1 -awned. Median (principal) awn
0–1.8 mm long overall. Palea 2 -nerved. Palea apex entire or dentate, muticous.
Anthers 3. Grain 1.5–3 mm long.
Continental
Distribution: Australasia.
Australian
Distribution: Western Australia, Northern Territory, South Australia,
Queensland.
Western Australia:
Dampier. Fortescue, Ashburton, Austin. Northern Territory: Victoria
River, Barkly Tableland, Central Australia North, Central Australia South. South
Australia: Lake Eyre. Queensland: Burke, Cook, Gregory North,
Gregory South, Maranoa, Mitchell, South Kennedy.
Notes.
Plants of this species are distinctive in the field due to their robust
tussock-forming habit, usually flat blades, and glabrous smooth, pruinose or
glaucous facies. The chief morphological features are florets that are longer
than glumes with divergent or recurved lemma and palea, vesicular blades, and
the long-acuminate, mucronate or aristulate, 2-grooved lemmas.
Endemic.
Between 16ºS and 28ºS in S.A., Qld, N.T. and W.A. A common, often dominant,
component of grassland plains, gibber plains and clay pans, in grey, brown or
black, cracking clays and other heavy-textured soils. Favourable sites are
usually low-lying, water-logged or seasonally flooded, and include waterholes,
swamps, the channels and banks of watercourses, gilgais, and floodouts. Flowers
and fruits Dec.-Sept. (summer to early-spring).
