Description:
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.
Cultivation:
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.
Range
& Habitat: 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.
Faunal
Associations: 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.
Photographic
Location: A waste area near a highway overpass and
railroad at the
National Dunes Lakeshore in NW Indiana. The photographed plants are a
nearly awnless variety of Wheat.
Comments:
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.