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 annual grass forms either solitary or tufted leafy culms about 2-3½' tall. These culms are light green, erect, terete, glabrous, and sometimes glaucous. Alternate leaves occur along the length of each culm. The flat leaf blades are 6-18 mm. across and 5-12' long; they are bluish or grayish green, glabrous, and sometimes glaucous. These blades are ascending, arching, or rather floppy. The bases of these blades often have rounded auricles with scarious (scar-like) wavy margins. The open leaf sheaths are bluish or grayish green, glabrous, and sometimes glaucous. On rare occasions, the lower leaf sheaths are pubescent. The ligules are short-membranous (about 1-2 mm. in length), while the nodes are swollen and glabrous. Each culm terminates in an erect floral spike about 2-4' long. The floral spikes are grayish or bluish green with darker markings; they are cylindrical-bristly in appearance. Each floral spike has multiple overlapping spikelets that are appressed against the rachis (central stalk of the spike); these spikelets are nearly erect. Each spikelet is 10-15 mm. in length, consisting of a pair of glumes at the bottom and 2-5 florets with lemmas above. The glumes are 9-11 mm. in length, ovate in shape, partially keeled, and glabrous. The lemmas are 10-13 mm. in length, ovate in shape, convex along their outer surfaces, and glabrous. Along the inner sides of the florets, are membranous paleas that are similar in size to the lemmas. At the apices of the glumes and lemmas, there are 1-2 small teeth. In some varieties of wheat, the glumes can have awns up to 30 mm. long, while the lemmas can have awns up to 80 mm. long. These awns are erect. Each floret consists of an ovary, a pair of feathery stigmata, and stamens. The blooming period usually occurs from late spring to mid-summer. The florets are cross-pollinated by the wind. They are replaced by grains that are 7.5-8.5 mm. long, 3.5-3.75 mm. across, and ovoid-ellipsoid in shape; the light-colored grains are convex on one side and incurved on the other side. The root system is fibrous.

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).

More wheat is produced annually than any other cereal crop. Overall, wheat is perhaps the single most important food crop for humans. It is grown throughout the temperate regions of the world, but only in the highlands of the tropics and subtropics. Major wheat producers include Russia, the United States, China, India, France, Canada, Australia, Turkey, Pakistan, and Argentina.

Wheat is among the most ancient of domesticated crops. It was apparently derived from wild species in the Fertile Crescent of southwestern Asia around 8000 B.C., together with Barley (Hordeum vulgare) and pulses. Einkorn (T. monococcum) and Emmer Wheat (T. turgidum dicoccum) represent early lineages of domesticated wheats. The grains of these species retain their hulls after threshing. Today, Einkorn and Emmer are grown only to a very limited extent. Modern Bread Wheat (T. aestivum) and Durum Wheat (T. turgidum durum) are "free-threshing", producing naked grains. After Bread Wheat entered cultivation, it spread into Europe, North Africa, and Asia. Through most of the 16th century, wheat was confined to these continents, but in the subsequent two centuries it was taken to North and South America and to South Africa. Somewhat later, it reached Australia and New Zealand.

The ability of domesticated wheat to exchange genes with certain other grasses is a potentially serious concern in light of expanding efforts to incorporate herbicide resistance and other traits--beneficial traits we would not want transferred to weeds--in new wheat varieties using genetic engineering. Hegde and Waines (2004) reviewed available literature on the reproductive ecology of Bread Wheat and on introgression (infiltration of genes) between Bread Wheat and its wild relatives in the genus Aegilops and with feral Rye (Secale cereale) in North America. Willenborg and Van Acker (2008) discussed aspects of the biology and ecology of Bread Wheat that make the transfer of traits between cultivated wheat and weeds more or less likely.

(Vaughan and Geissler 1997)

Hegde, S.G. and J.G. Waines. 2004. Hybridization and Introgression between Bread Wheat and Wild and Weedy Relatives in North America. Crop Science 44: 1145-1155.

Peng, J.H.H., D.F. Sun, and E. Nevo. 2011. Domestication evolution, genetics and genomics in wheat. Molecular Breeding 28(3): 281-301.

Vaughan, J.G. and C.A. Geissler. 1997. The New Oxford Book of Food Plants (revised and updated edition). Oxford University Press, New York.

Willenborg, C.J. and R.C. Van Acker. 2008. The biology and ecology of hexaploid wheat (Triticum aestivum L.) and its implications for trait confinement. Canadian Journal of Plant Science 88: 9971013.

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

Naturalized plants of non-native Wheat are occasional throughout Illinois. Wheat originated from the eastern Mediterranean or the Middle East in Eurasia. It is a major agricultural crop. Occasionally, Wheat escapes from cultivation and self-sows. However, such escaped plants do not persist in the environment for very long. Typical habitats of such plants include fields, roadsides, areas along railroads, areas near grain elevators, and open waste areas. Sometimes Wheat is deliberately planted as a source of food for wildlife and to control erosion along roadside embankments until perennial grasses become established. Wheat thrives in highly disturbed areas with exposed topsoil.

Nile region, oases, Mediterranean region, Sinai.

Grown almost throughout the world up to latitude 69.5°N.

Triticum vulgare Vill.:
Brazil (South America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Triticum sativum Lam.:
Bolivia (South America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Triticum aestivum L.:
Argentina (South America)
Bolivia (South America)
Brazil (South America)
Canada (North America)
Chile (South America)
Costa Rica (Mesoamerica)
Ecuador (South America)
El Salvador (Mesoamerica)
Ethiopia (Africa & Madagascar)
Greenland (North America)
Guatemala (Mesoamerica)
Honduras (Mesoamerica)
Mexico (Mesoamerica)
Peru (South America)
Uruguay (South America)
United States (North America)
Venezuela (South America)
Caribbean (Caribbean)
Colombia (South America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Throughout China [cultivated worldwide].

Canada

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Widely cultivated all over the world.

Widely cultivated.

Culms hollow, 60–130(–150) cm tall, ca. 5-noded; nodes glabrous. Leaf blade flat, 10–24 × 0.4–1.5 cm, usually glabrous. Spike lax or dense, usually narrowed distally, square or subsquare in cross section, 5–18 cm, with up to 29 spikelets; rachis disarticulating or tough and not disarticulating, margin ciliate; internodes 3–4 mm. Spikelets with 4–9 florets (distal florets sterile). Glumes laxly appressed or adnate to floret, ovate or elliptic, sometimes very hard, distinctly or indistinctly to obscurely keeled, pubescent or glabrous; keel sometimes prolonged at apex into shortish tooth; tooth apex subobtuse, acute, or tapering into short awn. Lemma oblong-lanceolate, pubescent or glabrous, awnless to long awned; awn usually divergent. Palea subequaling lemma. Anthers yellow or purplish. Caryopsis usually free from lemma and palea. Fl. and fr. Apr–Aug.

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.

Cultivated annuals or biennials; culms tufted, 6-7-noded; ligule short, membranous. Spike up to 10 cm long, rachis 2-3 mm long. spikelets 2-6-flowered, 10-15 mm long, upper ones sterile; rachilla about 1 mm long; glumes coriaceous, slightly membranous near the margins, ovate, strongly keeled on the upper half, 7-9-nerved, usually with tessellate nerves on the upper part; palea 2-keeled, narrowly winged, as long as the lemma; anthers 1.8-2 mm long. Caryopsis 5 mm long, hairy at the apex, enclosed between the lemma and palea, hilum linear; embryo 1/4 as long as the grain.

Naturalized plants of non-native Wheat are occasional throughout Illinois. Wheat originated from the eastern Mediterranean or the Middle East in Eurasia. It is a major agricultural crop. Occasionally, Wheat escapes from cultivation and self-sows. However, such escaped plants do not persist in the environment for very long. Typical habitats of such plants include fields, roadsides, areas along railroads, areas near grain elevators, and open waste areas. Sometimes Wheat is deliberately planted as a source of food for wildlife and to control erosion along roadside embankments until perennial grasses become established. Wheat thrives in highly disturbed areas with exposed topsoil.

Commonly cultivated, e.g., in fields of Hordeum and Triticum; below 3500 m.

Wheat attracts various insects that feed on the foliage, grains, roots, or plant juices. These insects include Chaetocnema denticulata (Toothed Flea Beetle), Diabrotica barberi (Northern Corn Rootworm), Myochrous denticollis (Southern Corn Leaf Beetle), and Oulema melanopus (Cereal Leaf Beetle); Sphenophorus callosus (Southern Corn Billbug), Sphenophorus destructor (Destructive Billbug), Sphenophorus minimum (Little Billbug), Sphenophorus parvulus (Bluegrass Billbug), and Sphenophorus venatus venatus (Hunting Billbug); Macrosiphum avenae (English Grain Aphid), Rhopalosiphum padi (Bird Cherry Oat Aphid), Schizaphis graminum (Greenbug), and Sipha flava (Yellow Sugar Cane Aphid); Euschistus servus (Brown Stink Bug), Euschistus variolarius (One-Spotted Stink Bug), and Oebalus pugnax pugnax (Rice Stink Bug); the shield bug Homaemus bijugis; Camnula pellucida (Clear-Winged Grasshopper), Dissosteira carolina (Carolina Grasshopper), Melanoplus femurrubrum (Reg-Legged Grasshopper), and Melanoplus sanguinipes (Migratory Grasshopper); and the caterpillars or cutworms of such moths as Achatodes zeae (Elder Shoot Borer Moth), Apamea amputatrix (Yellow-Headed Cutworm), Apamea finitima (Bordered Apamaea), Dargida diffusa (Wheathead Armyworm), Leucania pseudargyria (False Wainscot), Ochsenheimeria vacculella (Cereal Stem Moth), Peridroma saucia (Variegated Cutworm), and Rachiplusia ou (Gray Looper). A large number of geese, ducks, upland gamebirds, and granivorous songbirds eat the grains of Wheat (see the Bird Table for a listing of these species); this consists primarily of grains that have been left on the ground after harvest time. In addition, migrating geese often eat the young foliage of winter wheat along the Mississippi flyway during the spring. Among mammals, the grains are eaten by the Eastern Skunk, Spotted Skunk, Fox Squirrel, Eastern Chipmunk, Thirteen-Lined Ground Squirrel, House Mouse, Deer Mouse, and White-Footed Mouse. The Cottontail Rabbit and White-Tailed Deer sometimes browse on the young foliage. The young foliage can also be used as pasturage for cattle, horses, sheep, and other domesticated animals.

Foodplant / miner
larva of Agromyza mobilis mines leaf of Triticum aestivum
Other: sole host/prey

In Great Britain and/or Ireland:
Foodplant / feeds on
larva of Baliothrips graminum feeds on live ear of Triticum aestivum

Foodplant / parasite
Blumeria graminis parasitises live Triticum aestivum

Foodplant / internal feeder
larva of Cephus pygmeus feeds within stem of Triticum aestivum
Other: major host/prey

Plant / resting place / within
puparium of Cerodontha lateralis may be found in leaf-mine of Triticum aestivum
Other: major host/prey

Foodplant / feeds on
adult of Chirothrips manicatus feeds on live ear of Triticum aestivum

Foodplant / saprobe
Chytriomyces nodulatus is saprobic on submerged leaf of Triticum aestivum
Remarks: captive: in captivity, culture, or experimentally induced

Foodplant / saprobe
Entophlyctis aurea is saprobic on submerged leaf of Triticum aestivum

Foodplant / feeds on
larva of Helophorus nubilus feeds on Triticum aestivum

Foodplant / feeds on
adult of Limothrips cerealium feeds on live ear of Triticum aestivum
Remarks: season: 6-8
Other: major host/prey

Foodplant / feeds on
larva of Limothrips denticornis feeds on live leaf of Triticum aestivum

Foodplant / sap sucker
Macrosiphum avenae sucks sap of live Triticum aestivum

Foodplant / feeds on
adult of Oulema melanopus/rufocyanea agg. feeds on leaf of Triticum aestivum
Remarks: season: 1-12

Foodplant / feeds on
larva of Phalacrus corruscus feeds on Triticum aestivum

Foodplant / pathogen
Pseudocercosporella herpotrichoides var. acuformis infects and damages Triticum aestivum

Foodplant / spot causer
linear, long covered by epidermis telium of Puccinia striiformis var. striiformis causes spots on live inflorescence of Triticum aestivum
Other: major host/prey

Foodplant / pathogen
perithecium of Pyrenophora seminiperda infects and damages seed of Triticum aestivum
Remarks: captive: in captivity, culture, or experimentally induced

Foodplant / spot causer
mycelium of Rhizoctonia cerealis causes spots on live stem of Triticum aestivum

Foodplant / sap sucker
Rhopalosiphum padi sucks sap of Triticum aestivum

Foodplant / spot causer
crowded, arranged in rows or scattered, immersed, minute, fuscous pycnidium of Septoria coelomycetous anamorph of Septoria graminum var. crassipes causes spots on live leaf of Triticum aestivum
Remarks: season: 7

Foodplant / internal feeder
larva of Trachelus tabidus feeds within stem of Triticum aestivum
Other: major host/prey

Foodplant / feeds on
larva of Zabrus tenebrioides feeds on Triticum aestivum

Triticum aestivum (wheat (grass)) is prey of:
Lepus californicus
Lepus townsendii
Calamospiza melanocorys

Based on studies in:
USA: California, Cabrillo Point (Grassland)

This list may not be complete but is based on published studies.

Annual.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 10
Specimens with Barcodes: 13
Species With Barcodes: 1

Canada

Rounded National Status Rank: NNA - Not Applicable

United States

Rounded National Status Rank: NNA - Not Applicable

Rounded Global Status Rank: GNR - Not Yet Ranked

These species are introduced in Switzerland.

The preference is full sun, mesic to dry-mesic conditions, and soil containing loam or clay-loam. Some varieties of wheat (winter wheat) are planted during the fall, while other varieties (spring wheat) are planted during the spring.

Comments: Generally treated botanically as a species of cultivated or obscure origin "although it is not found in nature and its genome has been shown to be composed of those of" Triticum dicoccoides, T. speltoides, and T. tauschii" (cf. Intl. Code Botanical Nomen., St. Louis ed. (2000), Art. H3.3, Note 1, ex. 3 (regarding species of known hybrid origin not treated as hybrids). The name Triticum aestivum is nomenclaturally conserved over the sumiltaneously published Linnaean name T. hibernum (ICBN, St. Louis, 2000, p. 392.) LEM 17Oct01.