Ryegrass is a cool season perennial or annual grass with tufted or clustered growth and perennial strains have a glossy dark green leaves while annual strains can be brighter green which both are often purplish at the base. Ryegrass possesses a thin ligule with a folded leaf along its vein and overlapping or clasping auricles.
The seed heads appear in spring and early summer as a long, narrow spike with a long cluster of small dark seeds at the top.
Ryegrass is a difficult weed to control in turf due to its tolerance of close mowing heights and resistance to many herbicides. Perennial Rye with its dark green colour also makes it a desirable turf variety in some parts of the country and popular over sewing of warm season grasses.