Triticum aestivum L.

Annuals, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems with inflorescence 1-2 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly basal, below middle of stem, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath hairy, hispid or prickly, Leaf sheath hairy at summit, throat, or collar, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blade auriculate, Leaf blades 1-2 cm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligul e an unfringed eciliate membrane, Inflorescence terminal, Inflorescence a dense slender spike-like panicle or raceme, branches contracted, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence spike linear or cylindric, several times longer than wide, Inflorescence single raceme, fascicle or spike, Inflorescence branches more than 10 to numerous, Flowers bisexual, Spikelets sessile or subsessile, Spikelets laterally compressed, Spikelet 3-10 mm wide, Spikelets with 2 florets, Spikelets with 3-7 florets, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating above the glumes, glumes persistent, Spikelets disarticulating beneath or between the florets, Spikelets not disarticulating, or tardy, Spikelets closely appressed or embedded in concave portions of axis, Rachilla or pedicel glabrous, Glumes 2 clearly present, Glumes equal or subequal, Glumes shorter than adjacent lemma, Glumes awn-like, elongated or subulate, Glumes awned, awn 1-5 mm or longer, Glumes keeled or winged, Glume surface hairy, villous or pilose, Glumes 4-7 nerved, Glumes 8-15 nerved, Glumes 2-5 toothed, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma 5-7 nerved, Lemma glabrous, Lemma apex acute or acuminate, Lemma mucronate, very shortly beaked or awned, less than 1-2 mm, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn less than 1 cm long, Lemma awn 1-2 cm long, Lemma awned from tip, Lemma awns straight or curved to base, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea about equal to lemma, Palea 2 nerved or 2 keeled, Palea keels winged, scabrous, or ciliate, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear, Caryopsis hairy at apex.

Triticum aestivum, common or bread wheat, is an annual grass in the Poaceae (grass family) native to the Mediterranean region and southwest Asia, which is one of several species of cultivated wheat, now grown in temperate climates worldwide. Wheat one of the top two cereal crops grown in the world for human consumption, along with rice (Oryza sativa). (Corn, Zea mays, is grown in larger amounts than either rice or wheat, but a significant portion of it is used for livestock feed and biofuel, rather than human food).

Wheat is one of the most ancient of domesticated crops, with archaeological evidence of the cultivation of various species in the Fertile Crescent dating back to 9,600 B.C. The various species have been developed into thousands of cultivars (over 25,000, by one estimate) that differ in chromosome number from the primitive diploid types, with 7 pairs of chromosomes, to hybrid allopolyploids, with 14, 21, and 28 chromosome pairs. Cultivars are variously categorized according to their horticultural requirements (spring vs. winter wheat), texture and food uses (hard wheat, which often contains more gluten and is used for bread; vs. pastry or flour wheat, used for cakes, biscuits, and cookies), or by growth form and seed characteristics (the varieties aestivum, compactum, and spelta are among the six major categories recognized).

Wheat is high in carbohydrates, protein (although it lacks several essential amino acids), and vitamins B and E (if the grain is left whole) is used in countless breads and baked goods, and is an important source of calories for over 1 billion people in the world. Wheat can be refined into starch and wheatgerm oil, and wheat gluten (the proteins that make it sticky) is used in many products. Wheat is also used to make beer and as animal fodder.

The FAO estimates that global commercial production of all types of wheat was 650.9 million metric tons in 2010, harvested from 217.0 million hectares; it is grown on around 4% of the planet’s agricultural land. Leading producers were China, India, the U.S., the Russian Federation, and France. Within the U.S., the states that were leading producers include Kansas, Montana, North Dakota, South Dakota, Idaho, and Washington.

(Bailey et al. 1976, FAOSTAT 2012, Flora of China 2006, Hedrick 1919, USDA 2012, van Wyk 2005.)

Bread Wheat (Triticum aestivum) accounts for around 95% of the wheat grown in the world, with most of the remainder being Durum Wheat (T. durum) (Peng et al. 2011). Bread Wheat has both awned (i.e., with projecting glumes) and awnless forms. There are spring wheats (sown in spring and harvested in late summer) and winter wheats (sown in autumn and harvested in early summer). Grain color varies from yellow to red brown, but cultivars are usually described as white or red. They may also be classified as hard (vitreous endosperm) or soft (mealy endosperm). These characteristics are relevant to the milling process: milled particles from hard wheat flow freely through a sieve to produce a very clean flour; flour from soft wheat clumps together like fine powder and is difficult to sieve. Wheat flours are said to be strong (i.e., with relatively high protein content, which results in more elastic bread dough) or weak. Hard wheats are used to make bread; soft wheats are used for cakes, cookies, biscuits, and pastries.

To make leavened or porous bread, the basic ingredients are flour, water, yeast, and salt. These are mixed together to produce a dough which rises (because of yeast fermentation) and is then baked. Among the cereal grains, Bread Wheat is outstanding in its ability to produce leavened bread (other cereals, such as Rye and Durum Wheat, produce poorly leavened bread). This extraordinary ability depends on the wheat protein complex known as "gluten", which is elastic, expands during fermentation, and retains the released carbon dioxide to yield a porous bread. Without yeast, wheat flour produces a flat bread (e.g., the chapatis of the Indian subcontinent or matzah). The extraction of starch and gluten from the wheat grain or flour are well known industrial processes. Gluten may be added to bread to increase its protein content.

Some people suffer from coeliac disease, which results from a low tolerance for gluten (and therefore for wheat, Rye, Barley, and triticale).

(Vaughan and Geissler 1997)

(For more information, including background on the domestication and evolution of wheat, see Comprehensive Description and Triticum.)

This is the wheat that is used to make bread, pastry, and other food products. The grains are also used in making alcoholic beverages, industrial alcohol, and livestock feed. The old stems of wheat, or straw, is used as packing material, cattle bedding, mulch for gardens, and paper manufacturing. Because there are many varieties and subspecies of Wheat (Triticum aestivum), local populations of plants can vary somewhat in appearance. In particular, some varieties and subspecies of Wheat have abundant awns (referred to as 'Bearded Wheat'), while other varieties and subspecies are largely lacking in such awns. Wheat has been cultivated for thousands of years, beginning in the Middle East and ancient Egypt. From there, it eventually spread to Europe, and the European colonists brought wheat with them to North America. The closest relatives of Wheat in Illinois are the so-called wheatgrasses (Agropyron spp.), which were assigned to the Triticum genus at one time.