Common name: Grader Grass
Themeda quadrivalvis (L.) Kuntze APNI* 
Description: Glabrous annuals or perennials to 2 m tall, erect or geniculate at the base. Nodes glabrous.
Sheaths glabrous; ligule obtuse to truncate, 2–2.5 mm long, erose to ciliate; blade folded in bud, 5–13 mm wide, to 35 or more cm long.
Inflorescence paniculate, with a further 1–3 levels of branching, interrupted, up to c. 130 cm long, up to several-noded; spathe subtending the inflorescence similar to the culm leaves; as the level of branching increases the spathes (blade and sheath) becoming shorter, more strongly keeled, compressed, ± scabrous on the midrib, with membranous margins on the sheath and often with tubercle-based hairs along the margins of the lower 33% of the blade; spathes of ultimate branches (condensed racemes) papery to membranous, linear-lanceolate, keeled, glabrous, 15–20 mm long. Involucral spikelets male or neuter, subequal, strongly dorsally compressed, linear-lanceolate, 5–6 mm long; lower glume many-nerved, usually with tubercle-based hairs to 3.5 mm long on the upper 65% of the back, acute to acuminate, 2-keeled, usually only 1 keel winged or both broadly winged; upper glume subequalling the lower glume, 3-nervedmargins incurved with broad transparent extensions in the upper 50–65%; lemma 1, more or less transparent, c. 3.5 mm long, without a palea. Bisexual spikelet 5–6 mm long (including the attached joint and excluding the awn), narrowly oblong, sparsely pubescent to glabrous. Lower glume glabrous to sparsely hirsute, very convex on the back with incurved margins, the apex glabrous, obtuse to truncate; upper glume narrower than the lower, sparsely hirsute to glabrous, 4.5 mm long, with 2 very prominently thickened longitudinal lines on the inside which are seen on the back as deep longitudinal grooves. Sterile lemma transparent or absent; upper lemma not prominently nerved, stipe-like, glabrous, passing upwards into the robust, once or twice geniculate awn; awn shortly villous below, scabrous-pubescent to scabrous above, c. 4 cm long, the column and bristle almost equal; palea absent. Pedicellate spikelets neuter, usually 2, 4.5–5.5 mm long, on pedicels c. 1.5 mm long, passing inconspicuously into the spikelet; lower glume c. 13-nerved, linear-lanceolate, acute with incurved, membranous margins; upper glume subequalling and similar to the lower, 3-nerved, hyaline; lemma transparent or absent.
Flowering: summer.
Distribution and occurrence: Grows in disturbed sites, especially roadsides; north from Wauchope district. Native of Malesia.
NSW subdivisions: *NC
Other Australian states: *Qld
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.
|
