Triraphis Prodr. 185 (1810).
Derivation:. From Latin tri (three) and rhaphis (needle), referring to the 3 needle-like awns of the flowering glume.
Key references (keys and floras):. G.Bentham, Flora Australiensis 7: 603–605 (1878); C.A.Gardner, Flora of Western Australia 1 Gramineae 83–85 (1952); M.Lazarides, Flora of Central Australia 443 (1981); J.C.Tothill and J.B.Hacker, Grasses of Southern Queensland 418–419 (1983); J.P.Jessop, Flora of South Australia 4: 1949 (1986); B.K.Simon, Key to Australian Grasses 174 (1993); S.W.L.Jacobs and K.L.McClay, Flora of New South Wales 4: 562–563 (1993); N.G. Walsh, Flora of Victoria 2: 557 (1994); D.Sharp and B.K.Simon, AusGrass (2002); K.Mallet (ed.), Flora of Australia 44B: Poaceae 3: 424–426 (2005); J.P.Jessop, Grasses of South Australia 405 (2006); S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th ed, 389–390 (2008).
W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (324).
Native. 7 species, from tropical and southern Africa, Australia. 1 species in Australia, WA, NT, SA, Qld, NSW, and Vic.
Habit. Annual or perennial, tufted (mostly small xeromorphs). Leaf blades narrow. Ligule a fringed membrane or a fringe of hairs.
Inflorescence. Inflorescence paniculate, a spike-like panicle, open or contracted (rarely spiciform).
Spikelets. Spikelets laterally compressed, more than 2 flowered, with 2 or more fertile florets, awned, solitary, pedicelled; with naked rachilla extension. Fertile spikelets disarticulating above glumes.
Glumes. Glumes relatively large, unequal (rarely) or more or less equal, shorter than spikelet, shorter than adjacent lemmas, pointed or blunt (often bidentate), awned (or mucronate, from the sinus) or awnless, keeled, similar (narrow, persistent). Lower glume 1 nerved. Upper glume 1 nerved.
Florets. Fertile florets 5–10. Lemmas not becoming indurated (membranous), incised, deeply cleft (on either side of the central lobe), awned, 3 nerved, hairy (villous on the lateral nerves), 3 keeled or 1 keeled. Awns 3, the median similar in form to laterals, from a sinus (of the central lobe), non-geniculate (setiform). Lateral awns shorter than median. Palea shorter than the lemma, apically notched or deeply bifid, 2 nerved. Distal incomplete florets underdeveloped. Lodicules 2. Stamens 3. Grain small, linear, trigonous. Hilum short. Embryo large, with one scutellum bundle.
Kranz Anatomy. C4, biochemical type NAD-ME (T. mollis).
2n = 20, 2 ploid.
Habitat. Mesophytic to xerophytic. Savanna, in sandy or rocky soil. Species of open habitats.
Classification. Chloridoideae; Cynodonteae.
Types Species. T. mollis R.Br.
Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Africa.