Common name: Native Oatgrass, Oat Kangaroo Grass
Themeda avenacea (F.Muell.) Maiden & Betche APNI* 
Description: Robust, densely tufted perennials to c. 2 m tall, usually densely woolly at the base.
Lower sheaths densely woolly-villous with crimped hairs, subpersistent; ligule membranous, somewhat jagged, fringed at the back and sides with hairs 2–7 mm long; blade 1–1.5 mm wide.
Inflorescence glabrous, linear to linear-oblong, interrupted, rather loose, 15–100 cm long; upper spathes with rather expanded sheaths and short blades; spatheoles linear or linear-lanceolate, attenuate, 3–9 cm long; condensed racemes often erect, 1–2-jointed above the involucral spikelets. Involucral spikelets male, subequal, strongly dorsally compressed, linear-lanceolate, acuminate, 20–30 mm long; lower glume the longest, spatheole-like, many-nerved, in some spikelets both keels broadly winged, in other spikelets 1 keel winged and the other inconspicuous and not winged; upper glume 75–80% as long as the lower, narrowly truncate or attenuate at the apex, 3-nerved, 2-keeled; lower lemma almost equalling the upper glume, 1-nerved; palea extremely narrow, attenuate or absent; upper lemma a little shorter, but otherwise similar to the lower, without a palea. Bisexual spikelets densely villous with reddish-brown hairs, 5–7 mm long, narrowly oblong, c. 13–17 mm long including the attached joint and excluding the awn. Glumes cartilaginous, subequal in length, c. 8–10 mm long, obtuse; lower glume c. 11-nerved with nerves only visible on the inside, the margins slightly incurved; upper glume 3-nerved, with 2 prominently thickened longitudinal lines on the inside between the dorsal and lateral nerves. Sterile lemma 1-nerved, hyaline with inflexed margins almost equalling the glumes; palea very narrow, hyaline, short ciliate at the apex, or much reduced or absent. Fertile lemma linear-stipe-like, glabrous, passing upwards into the robust, once or twice geniculate awn; awn shortly villous below, scabrous-pubescent to scabrous above, 4–10 cm long, the column and bristle c. equal; palea absent. Pedicellate spikelets 1–2 on pedicels c. 5 mm long, similar in size and shape to the involucral spikelets, usually neuter.
Flowering: Flowers in response to rain.
Distribution and occurrence: Grows in depressions and floodways on good soil in drier regions.
NSW subdivisions: CC, NWS, CWS, NWP, NFWP
Other Australian states: Qld Vic. W.A. S.A. N.T.
Text by Jacobs, S.W.L., Whalley, R.D.B. & Wheeler, D.J.B.
Taxon concept: Grasses of New South Wales, Fourth Edition (2008).
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.
|
