Scientific Name
Lolium perenne L. ssp. multiflorum (Lam.) Husnot
Common Name(s)
Italian ryegrass
Tribe / Family Name
Poeae
Flowering Period
February to March
Symbol
LOPEM2
Description
Italian ryegrass is an introduced, annual or short-lived perennial bunchgrass. Culms are up to 150 cm in height. Its inflorescences are spikes 15-45 cm long with 5-38 alternately arranged spikelets attached directly to the rachis. Spikelets are 8-31 mm long, (10)11- to 22-flowered, and usually awned (awns are up to 15 mm long and attached just below the lemma tips). Generally, with two glumes, especially in the terminal spikelets; however, the inner glumes (the ones facing the rachis) are absent in the other spikelets. Auricles are up to 5 mm long. Ligules are up to 3 mm long and membranous. Blades are 4-30 cm long, up to 6 mm wide, and dark green with smooth, shiny and hairless under surfaces.
General Info
Italian ryegrass can be found along roadsides, in disturbed meadows, fields, waste areas, lawns, plains, foothills, and montane sites.
Similar Species
Italian ryegrass can look similar to other ryegrass (Lolium) species, especially perennial ryegrass (Lolium perenne). To differentiate these plants from each other, compare their heights, number of florets, presence of awns, and blade widths. For example, Italian ryegrass ranges up to 150 cm in height, has broader leaves (up to 10 mm wide), and 10- to 20-awned florets (awns up to 15 mm long), whereas perennial ryegrass ranges up to 100 cm in height, has skinner leaves (up to 5 mm wide), and 5- to 10-unawned or awn-tipped florets (awns up to 8 mm long). You can also distinguish these plants by their life spans: Italian ryegrass is an annual or short-lived perennial, and perennial ryegrass is a long-lived perennial.
Picture of growth habitat. Photo by Justin J. Trujillo.
Image of spike inflorescence. Photo by Justin J. Trujillo.
Close-up of spikelet. Photo by Justin J. Trujillo.
Close-up images of ligule and auricles. Photos by Justin J. Trujillo.
Illustration of Italian ryegrass. Hitchcock, A.S. (rev. A. Chase). 1/1/1950.