Tripogon

Tripogon Syst. Veg. 2: 34, 600 (1817).

Derivation:. From Latin tri (three) and pogon (beard), referring to the 3-nerved lemma with the mid-nerve protruding to a short awn.

Key references (keys and floras):. C.A.Gardner, Flora of Western Australia 1 Gramineae 205–207 (1952); E.E.Henty, Manual Grasses New Guinea 189 (1969); M.Lazarides, Tropical Grasses S.E. Asia 179 (1980); M.Lazarides, Flora of Central Australia 461 (1981); J.C.Tothill and J.B.Hacker, Grasses of Southern Queensland 416–417 (1983); J.P.Jessop, Flora of South Australia 4: 1948–1949 (1986); M.Lazarides, F.Quinn and J.Palmer, Flora of the Kimberley Region 1236–1238( (1992); B.K.Simon, Key to Australian Grasses 173 (1993); S.W.L.Jacobs and K.L.McClay, Flora of New South Wales 4: 531 (1993); N.G. Walsh, Flora of Victoria 2: 559–560 (1994); D.Sharp and B.K.Simon, AusGrass (2002); K.Mallet (ed.), Flora of Australia 44B: Poaceae 3: 422–423 (2005); J.P.Jessop, Grasses of South Australia 403–405 (2006); S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th ed, 389 (2008).

W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (601).

Native. About 30 species, from Old World tropics. 1 species in Australia, WA, NT, SA, Qld, NSW, and Vic. Also New Guinea and Malesia.

Habit. Annual or perennial, tufted. Leaf blades narrow. Ligule an unfringed membrane to a fringe of hairs.

Inflorescence. Inflorescence a single spike (slender), a single raceme or spike.

Spikelets. Spikelets all partially embedded in rachis, laterally compressed, more than 2 flowered, with 2 or more fertile florets, solitary, sessile; with naked rachilla extension. Fertile spikelets adaxial (with lower glume against rachis), disarticulating above glumes.

Glumes. Glumes unequal to more or less equal, shorter than spikelet, shorter than adjacent lemmas to long relative to adjacent lemmas, hairless, glabrous, awnless, keeled, dissimilar or similar (membranous, narrow, the lower glume often asymmetric). Lower glume 1 nerved. Upper glume 1 nerved or 3 nerved or 5 nerved.

Florets. Fertile florets 3–20. Lemmas not becoming indurated (scarious with hyaline margins), mucronate or awned (usually awned or mucronate from a median sinus or behind the apex, the lobes sometimes awned or mucronate), 1–3 nerved, glabrous, 1 keeled. Awns when present 1 or 3 or 5, the median similar in form to laterals (when laterals present), from a sinus or apical, non-geniculate, much shorter than body of lemma to much longer than body of lemma. Palea entire (truncate) or apically notched, 1 nerved or 2 nerved. Palea keels usually winged (below). Distal incomplete florets underdeveloped. Callus short. Lodicules 2. Stamens 1 or 3. Grain small, terete or trigonous. Hilum short. Embryo large or small (1/3 the length of the fruit or somewhat less).

Kranz Anatomy. C4.

2n = 20.

Habitat. Helophytic to xerophytic. Species of open habitats.

Classification. Chloridoideae; Cynodonteae.

Notes. The genus is quite closely related to Leptochloa (Clayton and Renvoize, 1986).

Types Species. T. bromoides Roem. & Schult.

Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Gondwanan.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith