Italian Rye Grass
Lolium multiflorum
Grass family (Poaceae)

Description: This grass is usually an annual, although sometimes it is a biennial or short-lived perennial. It consists of a flowering culm with alternate leaves about 1-3' tall. The culm is pale green, terete, glabrous, and unbranched. The blades of the alternate leaves are up to 8" long and 1/3" (8 mm.) across; they are ascending to widely spreading, linear in shape, and rather floppy. The blades are medium green on both sides, shiny, and hairless; the base of each blade is wider than the sheath or the culm, around which there extends a pair of auricles. The leaf sheaths are pale green to pale reddish green, hairless, and longitudinally veined. At the apex of the culm, there develops a floral spike about 6-10" long, consisting of alternate spikelets along the rachis (flowering stalk). These spikelets are located edgewise along the rachis. The culm often undulates from one spikelet to the next. Each spikelet consists of a single outer glume and 8-20 lemmas with florets. In each spikelet, the ascending lemmas are arranged in 2 overlapping ranks. The glume (8-12 mm. in length) is longer than the lemmas, but shorter than length of the spikelet; it is linear-elliptic, convex along its outer surface, where there are 3-5 longitudinal veins. Each lemma is 6-8 mm. in length, linear-elliptic, and convex along its outer surface, where there are several longitudinal veins. The upper lemmas have awns (shorter than the length of the lemmas), while the lower lemmas frequently lack awns. Each lemma has a single floret with an ovary, 3 stamens, and a pair of feathery stigmata. The blooming period can occur from late spring to fall, but lasts only 2 weeks. The florets are wind-pollinated. Each fertile floret is replaced by an elongated grain. The root system is fibrous. This grass spreads by reseeding itself.

Cultivation: The preference is full or partial sun, moist to dry-mesic conditions, and fertile loam, although other kinds of soil are tolerated. Growth and development are rapid, but this grass is short-lived.

Range & Habitat: Italian Rye Grass is scattered across Illinois, where it is uncommon to occasional (see Distribution Map). This non-native grass was introduced into North America from Europe. Naturalized habitats include disturbed meadows, roadsides, fields, and waste areas. This grass usually doesn't persist in such habitats. It is still cultivated as a source of quick vegetative cover where the ground has been exposed by various development projects. It is also used as a source of forage, particularly in the southern states.

Faunal Associations: Insects that feed on Italian Rye Grass include the flea beetle Chaetocnema pulicaria, Rhopalosiphum padi (Bird Cherry / Oat Aphid), Nephelodes minians (Bronzed Cutworm), and Pediasia trisecta (Larger Sod Worm). Cattle, sheep, and other domesticated farm animals readily graze on the foliage, particularly while it is still young and immature. When this grass is planted near bodies of water, Canada Geese also like to feed on the foliage.

Photographic Location: A roadside bank in Urbana, Illinois, where this grass was planted deliberately for erosion-control.

Comments: As a result of the alternating spikelets, the floral spikes of Lolium spp. (Rye Grasses) have a distinctive appearance. These grasses are unusual in having only one glume per spikelet, instead of two. There are two other species in this genus that have naturalized in Illinois. Italian Rye Grass can be distinguished from Lolium perenne (English Rye Grass) by the more numerous lemmas in its spikelets (8 or more), which are frequently awned. It also differs from another species, Lolium tremulentum (Darnel), by having glumes that are shorter than spikelets. Another scientific name of Italian Rye Grass is Lolium perenne multiflorum.