Volume V (2000) - Flora of New Zealand Gramineae
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Themeda Forssk.

Themeda Forssk., 1775

Type species: T. triandra Forssk.

Rather tall and coarse, tufted perennials or annuals. Leaf-sheath variable. Ligule membranous, ± ciliate. Leaf-blade flat or folded. Culm leafy. Inflorescence a loose panicle, the axils of uppermost culm-leaves bearing lateral branches topped by a cluster of spikelets; each cluster subtended by a spathe and composed of 1-3 spikelet-fascicles; each fascicle further subtended by a smaller spathe-like bract and consisting of an involucre of 2 paired, ± sessile, ♂ or Ø spikelets surrounding a pair (or terminal triplet) of spikelets; one spikelet sessile, ⚥, the other 1 or 2 spikelets pedicelled, ♂ or Ø. Rachis of spikelet-cluster terete, glabrous, disarticulating above the involucre of spikelets and below the paired spikelets. All spikelets 2-flowered; lower floret often reduced to empty lemma, upper floret ⚥ in sessile member of spikelet-pair, ♂ or Ø in involucral spikelets and in pedicelled spikelets. Involucral spikelets and pedicelled spikelets with 2-keeled, ± herbaceous lower glume, and membranous, rarely 0, upper glume; both florets present, ♂ or Ø, or one or both suppressed, lemmas hyaline, and upper floret with or without palea. Sessile spikelet of spikelet-pair terete, often awned, with acute to pungent densely bearded callus; lower floret Ø, upper floret ⚥; glumes equal, coriaceous, lower tightly involute, very obscurely nerved, upper 3-nerved, with deep longitudinal groove on each side; lemmas unequal, lower hyaline, nerveless, upper consisting of a short base and a stiff geniculate awn, rarely awn reduced; palea hyaline, nerveless, small, or 0; lodicules 2, rather large, glabrous; stamens 3; ovary apex glabrous, stigmas subterminal or median; caryopsis subterete, embryo c. ½ length of caryopsis, hilum punctiform or shortly elliptic.

c. 16 spp., from tropical to warm temperate regions especially in South-East Asia and Australia. Naturalised sp. 1.

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