Eriachne ovata Nees. London J. Bot.
2: 416 (1843).
Classification. (GPWG 2001) : Subfamily
Micrairoideae. Eriachneae.
Type of Basionym or
Protologue Information: HT: Toward 4, Australia: Western Australia:
Sout-west Province: Swan River (CGE; IT: B).
Recent synonyms:
E. ovata var. villosa.
Key references
(books and floras): [1878] G.Bentham, Flora Australiensis 7 (630),
[1952] C.A.Gardner, Flora of Western Australia 1 Gramineae (50),
[2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia, [2006]
J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia (421).
Illustrations:
[2005] K.Mallet (ed.), Flora of Australia 44B: Poaceae 3
(frontispiece), [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South
Australia (423, fig. 353 & plate
16).
Habit.
Perennial. Rhizomes absent or present, elongated. Culms 3–42 cm tall. Mid-culm
nodes glabrous or pubescent. Lateral branches simple. Leaves mostly basal.
Ligule a fringe of hairs. Leaf-blades curved or flexuous, filiform, convolute,
1 mm wide. Leaf-blade surface scabrous or papillose, glabrous or indumented.
Inflorescence.
Inflorescence compound, a panicle. Panicle oblong or ovate, 1.5–5 cm long, 1–4
cm wide.
Spikelets.
Spikelets pedicelled. Fertile spikelets 2-flowered, both fertile, comprising 2
fertile floret(s), without rachilla extension, ovate, laterally compressed, 7–8
mm long.
Glumes.
Glumes similar, thinner than fertile lemma. Lower glume lanceolate or oblong,
membranous, without keels, 9–13 -nerved. Lower glume surface glabrous or
indumented. Upper glume lanceolate or oblong, 5–8 mm long, membranous, without
keels, 9–13 -nerved. Upper glume surface smooth, glabrous or indumented.
Florets.
Fertile lemma 6–10 mm long, without keel, 5–7 -nerved. Lemma surface
indumented. Lemma apex muticous. Palea apex entire or dentate, muticous. Grain
1.8–2.5 mm long.
Continental
Distribution: Australasia.
Australian
Distribution: Western Australia, South Australia.
Western Australia:
Gardner, Fitzgerald. Canning, Fortescue, Ashburton, Carnarvon, Austin.
Drummond, Avon, Coolgardie. South Australia: North-western, Lake Eyre,
Gairdner-Torrens Basin.
Notes.
Variable in size, indumentum and panicle form. Eriachne ovata is closely
allied to E. flaccida, which in turn is related to E. benthamii.
In overlapping areas of distribution, putative hybrids may occur which present
a complex of intermediate features between all three species. In their typical
condition, plants of E. ovata on comparison with those of E. flaccida
are smaller, usually hairy to a greater or lesser degree, and have shorter,
broader panicles and larger spikelets. Also, the two grooves on the lemma are
not always obvious as grooves are present often between all the nerves.
Furthermore, the acuminate lemma and palea, the dissimilarity in texture
between the lower and upper parts of the lemma, and the often entirely bearded
callus are distinguishing features of E. ovata.
Endemic.
SW W.A. (W of 121ºE and S of 26ºS) and northern S.A. Sandplains or in
association with granite. Flowers and fruits June-Feb. (early-winter to
early-summer), commonly Sept.-Oct. (spring).
