Elytrigia repens aristata
Grass family (Poaceae)
Description: This introduced grass is about 2-3' tall and unbranched, although it may tiller at the base and send up multiple culms. The culms are green, terete, and hairless. Along each culm are 3-6 alternate leaves. Each leaf blade is up to 8" long and 1/3" (10 mm.) across, or a little larger in size; it is dull green or greyish blue, ascending at the base near the culm, and curving outward or downward toward its tip. The upper surface of the leaf blade is hairless to sparsely short-pubescent and rough, while the lower surface is hairless and more smooth-textured. At the base of each leaf blade, there is a pair of slender auricles (ear-like lobes) that wrap around the culm. Each leaf sheath is dull green or greyish blue, and either hairless or pubescent. The culm terminates in a spike-like raceme up to 8" long that is stiff and erect. Along this raceme are spikelets up to 2/3" (20 mm.) long that alternate along each side of its central axis on short peduncles. These spikelets are appressed to slightly spreading and dull green to greyish blue; with maturity, they become light brown or straw-colored. Each spikelet consists of a pair of glumes at the bottom and 3-7 florets with their pairs of lemmas above. In each spikelet, the pairs of lemmas are densely crowded together. Each glume is about 1/3" (10 mm.) long and linear-lanceolate in shape; there are several fine longitudinal veins along its outer surface. The tip of each glume is acute or short-awned. Each lemma is about 1/3" long and linear to linear-lanceolate in shape. The typical form of Quack Grass has awnless lemmas (or with short insignificant ones), while f. aristata has lemmas with awns up to 1/3" (10 mm.) long. The short blooming period occurs during the summer; the florets are wind-pollinated. Upon maturity, each spikelet easily detaches from its base and falls in its entirety to the ground; the individual glumes and lemmas do not separate as readily from each other. The individual grains are pale yellow to light tan, oblongoid, and somewhat flattened. The root system is fibrous and produces long rhizomes. Vegetative colonies are often formed.
Cultivation: This adaptable grass is typically found in sunny areas that are moist to slightly dry in various kinds of soil, including those containing loam, clay-loam, gravel, and sand. Quack Grass produces a chemical that can suppress the growth of other plants; it is weedy and aggressive, particularly in the northern areas of the state.
Range & Habitat: Quack Grass is common in central and northern Illinois, while in the southern part of the state it is uncommon (see Distribution Map). The distribution map applies to the typical unawned form of Quack Grass, Elytrigia repens repens, which is far more common than the awned form, Elytrigia repens aristata, within the state. According to official records, the awned form has been collected in Cook County only. However, the webmaster found a colony of the awned form of Quack Grass growing in Champaign County, Illinois; it probably occurs in other counties as well. This grass was introduced from Europe, probably as a contaminant of imported grain or hay. It also occurs in parts of Asia. Habitats include scrubby barrens, pastures, abandoned fields, weedy meadows, edges of yards and gardens, areas along roadsides and railroads, mined land, and waste areas. This species prefers areas with a history of disturbance. Sometimes it is deliberately planted in pastures and along slopes for erosion control.
Faunal Associations: The caterpillars of the moth Leucania multilinea (Many-Lined Wainscot) and the skipper Polites mystic (Long-Dash) feed on the foliage of Quack Grass. Other insects feeding on Quack Grass include various plant bugs, Commellus comma (Leafhopper sp.), and Melanoplus bivittatus (Two-Striped Grasshopper). The seeds are eaten to a limited extent by some birds (e.g., Ring-Necked Pheasant, Snow Bunting), while the foliage is palatable to hoofed mammalian herbivores (e.g., cattle & horses). White-Tailed Deer and the Cottontail Rabbit eat Quack Grass to a limited extent.
Photographic Location: Along a railroad in Champaign, Illinois.
Comments: This grass has a rather coarse appearance. It is still referred to as Agropyron repens (Quack Grass) by many authors, which is a scientific synonym for this species. Quack Grass usually has leaf blades that are 1/4" to 1/3" across, while other Agropyron spp. (Wheat Grasses) in Illinois have more slender leaf blades (up to 1/5" across). This genus of grasses occurs primarily in dry sunny areas of the plains and western states. Recently, some species in this genus have been reassigned to either the Elytrigia or Elymus genus. Most of these species have spikelets in which the individual glumes and lemmas are easily separated from each other; individual spikelets do not detach in their entirety from their peduncles. Exceptions are Quack Grass and Elytrigia smithii (Western Wheat Grass, formerly known as Agropyron smithii), which have glumes and lemmas that are more difficult to separate from each other. This latter species has more narrow leaf blades than Quack Grass, as described above. Another species, Elymus pauciflorus subsecundus (Bearded Wheat Grass, formerly known as Agropyron subsecundum), resembles the awned form of Quack Grass somewhat. However, the lemmas of Bearded Wheat Grass have awns that are longer than 1/3" in length, while the lemmas of Quack Grass have shorter awns than this.