Triticum* Sp. Pl. 85 (1753).
Derivation:. Latin, an old name for wheat.
Taxonomic revisions, nomenclatural references:. Á.Löve, Feddes Repert. 95: 498–499 (1984).
Key references (keys and floras):. C.A.Gardner, Flora of Western Australia 1 Gramineae 197–198 (1952); J.C.Tothill and J.B.Hacker, Grasses of Southern Qld 422–423 (1983); J.P.Jessop, Flora of South Australia 4: 1886–1887 (1986); B.K.Simon, Key to Australian Grasses 174 (1993); S.W.L.Jacobs and K.L.McClay, Flora of New South Wales 4: 600–601 (1993); N.G. Walsh, Flora of Victoria 2: 520 (1994); D.I.Morris, Student's Flora of Tasmania 4B: 303–304 (1994); E.Edgar and H.E.Connor, Flora of New Zealand 5: 416–418 (2000); D.Sharp and B.K.Simon, AusGrass (2002); J.P.Jessop, Grasses of South Australia 279 (2006); S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th ed, 391–392 (2008); A.Wilson (ed.), Flora of Australia 44A: Poaceae 2: 105–107 (2009).
W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (242).
Naturalised. 8 species, from Europe, Mediterranean, Western Asia. 1 species in Australia, WA, SA, Qld, NSW, Vic, and Tas. Also New Zealand.
Habit. Annual, tufted. Leaf blades broad to narrow. Ligule an unfringed membrane.
Inflorescence. Inflorescence a single spike (elongated), a single raceme or spike. Spikelet-bearing axes when fragile, disarticulating at joints (above or below the spikelet).
Spikelets. Spikelets all partially embedded in rachis or not all embedded, laterally compressed, more than 2 flowered, with 2 or more fertile florets, solitary, sessile (with broad side facing axis); with naked rachilla extension. Fertile spikelets disarticulating above glumes or falling with glumes or not disarticulating (in cultivated forms).
Glumes. Glumes more or less equal, shorter than adjacent lemmas or long relative to adjacent lemmas, obtuse or truncate or incised, awned (or mucronate) or awnless, keeled (at least above, before the grain expands), with keel conspicuously winged or without a median keel-wing, similar (ovate or oblong, chartaceous or rarely membranous). Lower glume 5–11 nerved. Upper glume 5–11 nerved.
Florets. Fertile florets 2–6. Lemmas similar in texture to glumes to decidedly firmer than glumes, becoming indurated, entire at apex to incised (1 to several dentate, or acuminate), muticous or awned, 5–11 nerved, with nerves non-confluent, hairy or glabrous (but scabrid), not keeled or 1 keeled (at least above). Awns when present, 1, from a sinus or apical, non-geniculate, much shorter than body of lemma to much longer than body of lemma. Palea relatively long, entire (not split or divided at maturity) or apically notched, 2 nerved. Palea keels somewhat winged. Distal incomplete florets usually 1 or 2, underdeveloped. Callus very short, blunt. Lodicules 2. Stamens 3. Grain medium sized, ellipsoid, longitudinally grooved, compressed dorsiventrally or terete, with hairs confined to a terminal tuft. Hilum long-linear. Embryo large or small.
Kranz Anatomy. C3.
2n = 42 or 14 and 28, 6 ploid or 2 and 4 ploid, commonly adventive.
Habitat. Mesophytic, xerophytic. Stony hillsides, dry grassland, weedy places. Species of open habitats.
Classification. Pooideae; Triticeae.
Notes. Wheat was domesticated in the Near East some time prior to 7000 BC, and provides a classical example of evolution through polyploidy. There are three ploidy levels and within each level selection has proceeded from wild species, to hulled cultivated species whose grain is tightly invested by lemma and palea, and thence to free-threshing naked species. (Clayton and Renvoize, 1986).
Types Species. T. aestivum L.
Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Naturalised.