Italian ryegrass (Lolium multiflorum) is often confused with perennial ryegrass and was recently reclassified as a sub-species of perennial ryegrass. The most identifying characteristic are the waxy undersides of the leaves. It also has auricles (appendages) at the collar. The auricles are relatively uncommon in grass species.
Italian ryegrass is used as a cover crop on roadsides for reclamation of those areas, and is also used as a forage. It can at times escape cultivation and become established as a weed. It thrives on fertile soils and mild climates.
It has a low tolerance for hot and dry climates and harsh climates during the winter. The Mississippi Delta during the wintertime, provides a nearly perfect environment for Italian ryegrass.
It begins emerging in the fall, usually when temperatures are consistently below 90 degrees. Peak emergence occurs in the fall, but you will also see emergence throughout the winter and sometimes into the spring.
It’s classified as a winter annual, but often behaves as a biennial or a short-lived perennial that grows vigorously during the fall and can also grow through the winter and early spring. If conditions are right, it will continue to grow through the summer. It cross-pollinates openly creating hybrids across species of Lolium and it propagates exclusively by seeds.
These seeds are relatively large for grass seeds, so there is not a lot of dispersal far from the parent plant. A lot of the long distance dispersal is a product of human activity.