Triticum

Bread wheat Triticum aestivum, copyright I. V. Gashkova.

Belongs within: Pooideae.

Triticum, wheat, is a not particularly large but commercially very significant genus of grasses, with some species being among the world’s most widely grown grains.

Characters (from L. A. Morrision, in Flora of North America Editorial Committee 2007): Plants annual. Culms 14–180 cm, solitary or branched at the base; internodes usually hollow throughout in hexaploids, usually solid for about 1 cm below the spike in diploids and tetraploids, even if hollow below. Sheaths open; auricles present, often deciduous at maturity; ligules membranous; blades flat, glabrous or pubescent. Inflorescences usually terminal spikes, distichous, with 1 spikelet per node, occasionally branched; internodes (0.5)1.4–8 mm; disarticulation in the rachis, the spikelets usually falling with the internode below to form a wedge-shaped diaspore, sometimes falling with the adjacent internode to form a barrel-shaped diaspore, domesticated taxa usually non-disarticulating, or disarticulating only under pressure. Spikelets 10–25(40) mm, usually 1–3 times the length of the internodes, appressed to ascending, with 2–9 florets, the distal florets often sterile. Glumes subequal, ovate, rectangular, or lanceolate, chartaceous to coriaceous, usually stiff, tightly to loosely appressed to the lower florets, with 1 prominent keel, at least distally, keels often winged and ending in a tooth or awn, a second keel or prominent lateral vein present in some taxa; lemmas keeled, chartaceous to coriaceous, 2 lowest lemmas usually awned, awns 3–23 cm, scabrous, distal lemmas unawned or awned, awns to 2 cm; paleas hyaline-membranous, splitting at maturity in diploid taxa; anthers 3. Caryopses tightly (hulled wheats) or loosely (naked wheats) enclosed by the glumes and lemmas, lemmas and paleas not adherent; endosperm flinty or mealy. x = 7. Haplomes A, B, D, and G.

<==Triticum
    |--T. aegilopoidesD51
    |    |--T. a. var. aegilopoidesD51
    |    `--T. a. var. baidaricumD51
    |--T. aestivumBRW02
    |--T. caninumC55
    |--T. compactumD37
    |--T. diococcoidesG52
    |--T. dicoccumD51
    |--T. durumD51
    |--T. machaKSM06
    |--T. monococcumC96
    |--T. orientaleD17
    |--T. persicumD37
    |--T. polonicumD37
    |--T. pyramidaleD37
    |--T. sativumC06
    |--T. speltaD51
    |--T. sphaerococcumD37
    |--T. taushiiKSM06
    |--T. thaoudarD37
    |--T. timopheeviD51
    |--T. turgidum [incl. T. compositum]C55
    |    |--T. t. var. turgidumE-SM02
    |    `--T. t. var. carthlicumE-SM02
    `--T. vulgare [incl. T. hybernum]C55

*Type species of generic name indicated

References

[BRW02] Bowman, R. A., J. D. Reeder & B. J. Wienhold. 2002. Quantifying laboratory and field variability to assess potential for carbon sequestration. Communications in Soil Science and Plant Analysis 33 (9–10): 1629–1642.

[C96] Campbell, N. A. 1996. Biology 4th ed. The Benjamin/Cummings Publishing Company, Inc.: Menlo Park (California).

[C55] Candolle, A. de. 1855. Géographie Botanique Raisonée: Ou exposition des faits principaux et des lois concernant la distribution géographique des plantes de l’époque actuelle vol. 2. Librairie de Victor Masson: Paris.

[C06] Cheeseman, T. F. 1906. Manual of the New Zealand Flora. John Mackay, Government Printer: Wellington.

[D17] Diels, L. 1917. Beiträge zur Flora der Zentral-Sahara und ihrer Pflanzengeographie. Nach der Sammelausbeute des Freiherrn Hans Geyr von Schweppenburg. Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 54 (Beiblatt 120): 51–155.

[D37] Dobzhansky, T. 1937. Genetics and the Origin of Species. Columbia University Press: New York.

[D51] Dobzhansky, T. 1951. Genetics and the Origin of Species 3rd ed. Columbia University Press: New York.

[E-SM02] Ellneskog-Staam, P., & A. Merker. 2002. Screening for resistance to powdery mildew and brown rust in wheat-Leymus racemosus and wheat-Thinopyrum junceiforme alloploids. Acta Agricultura Scandinavica Section B—Soil and Plant Science 52: 158–161.

Flora of North America Editorial Committee. 2007. Flora of North America North of Mexico vol. 24. Magnoliophyta: Commelinidae (in part): Poaceae, part 1. Oxford University Press.

[G52] Gardner, C. A. 1952. Flora of Western Australia vol. 1 pt 1. Gramineae. William H. Wyatt: Perth.

[KSM06] King, R. C., W. D. Stansfield & P. K. Mulligan. 2006. A Dictionary of Genetics 7th ed. Oxford University Press.

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