Description: Tufted perennials or annuals.
Ligule membranous, ± ciliate; blade folded or flat. Inflorescence a loose, leafy panicle of groups of condensed racemes each subtended by a spathe, 1 or more such racemes subtended by larger spathes which may end in short blades.
Inflorescence a loose, leafy panicle of groups of condensed racemes each subtended by a spathe, 1 or more such racemes subtended by larger spathes which may end in short blades. Spikelets dissimilar, with 4 subterminal, sessile, male or barren spikelets forming an involucre to 1 (rarely more) sessile, bisexual spikelet and 1–2 pedicellate male or neuter spikelets, the whole enclosed by a spathe; the rachis disarticulating below the terminal triplet and tardily between the subtending spikelets. Sessile spikelet with a densely bearded acute or sharp callus; 1 fertile floret above a sterile floret. Glumes equal, leathery; lower tightly involute, obscurely-nerved; upper glume 3-nerved with a deep longitudinal groove on each side. Lemmas unequal, the lower small, nerveless, the upper consisting of a short base and stiff, geniculate awn, rarely with the awn reduced. Paleas small or absent. Pedicellate spikelets similar to the involucral spikelets but narrower, dorsally compressed, awnless; glumes subequal, the lower 2-keeled, green; upper glume hyaline, rarely absent; a lemma may be present but palea usually absent.
Distribution and occurrence: World: c. 18 spp., Old World. Aust.: 5 spp. (3 spp. native, 2 spp. naturalized), all States.
Text by Jacobs, S.W.L., Whalley, R.D.B. & Wheeler, D.J.B.; edited RW Jobson (Nov 2023).
Taxon concept: Grasses of New South Wales, Fourth Edition (2008).
| | Key to the species | |
| 1 | Glumes of the involucral spikelets (sterile or male spikelets) with long, tubercle-based hairs towards the tip, otherwise glabrous; annual with leaves folded in bud | Themeda quadrivalvis |
| Glumes of the involucral spikelets without tubercle-based hairs but sometimes with other types of hair; perennials with leaves folded or rolled in bud | 2 |
| 2 | Involucral spikelets glabrous, 20–30 mm long, in 2 separate pairs 1 slightly above the other; leaves rolled in bud | Themeda avenacea |
| Involucral spikelets hairy or glabrous, 6–12 mm long, in a ring arising at the same level; leaves folded in bud
Back to 1 | Themeda triandra |
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