Spinifex L.
Type species: S. squarrosus L.
Stout, dioecious perennials, with much-branched, far-creeping stolons; or tussock-forming. Leaf-sheath loose, open. Ligule a ciliate rim. Leaf-blade long, ± convolute, often silky-hairy. ♂ and ♀ inflorescences very dimorphic, the ♂ hemispherical, the ♀ globular, both consisting of clusters of racemes subtended by large bract-like spatheoles, individual racemes subtended by smaller 2-keeled bracteoles; racemes in ♂ plants pedunculate, bearing several spikelets and terminating in a short bristle; racemes in ♀ plants bearing only one spikelet near base and rachis much prolonged to a scabrid bristle. Spikelets 2-flowered, sometimes 1-flowered in ♀ plants. ♂ spikelet: glumes ½ length to ≈ spikelet, unequal, 3-9-nerved, ± chartaceous, ovate-oblong, entire, glabrous or hairy; lemma of lower and upper ♂ florets similar, 3-7-nerved, lanceolate, coriaceous, glabrous or hairy; palea ± similar to lemma in size and texture, strongly 2-keeled; lodicules small, broadly obovate, ± dentate, often ± united; stamens 3 in each floret; ovary rudimentary. ♀ spikelet: glumes ≈ spikelet, 3-9-nerved, chartaceous, ovate to lanceolate, entire, glabrous or hairy; lemmas of lower and upper floret equal or ± unequal, = spikelet, nerves 3 or 0, ± chartaceous, glabrous; lower floret Ø or 0, sometimes without palea, lodicules small, stamens 3, small, rudimentary on flattened filaments, rarely polliniferous; upper floret ♀, palea ± similar to lemma, lodicules larger, stamens 3, longer, on flattened filaments, pollenless or rarely polliniferous, ovary apex glabrous and long plumose stigmas, caryopsis enclosed in, but free from, hardened anthoecium; embryo large; hilum punctiform.
4 spp., 3 indigenous to Australia, 1 to Indomalesia. The 1 indigenous N.Z. sp. is found also in Australia.
