Common Name: ryegrass, perennial
Species: Lolium perenne L.
Bayer Code: LOLPE

Perennial ryegrass is a bunch-type grass that is used for winter overseeding on sites where high quality and winter color are needed. The texture, color, and density of perennial ryegrass are very similar to those of Kentucky bluegrass. Perennial ryegrass is often utilized for winter overseeding on golf course fairways and teeboxes, athletic fields, and high profile home lawns. Perennial ryegrass is often confused with tall fescue and/or Kentucky bluegrass. However, Kentucky bluegrass has a boat-shaped leaf tip and distinctive light-colored lines on both sides of the midrib. Tall fescue has rough leaf blade margins whereas perennial ryegrass has smooth ones. Also, tall fescue has rolled vernation in the leaf bud and perennial ryegrass has folded vernation.
perennial ryegrass
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perennial ryegrass vernation
perennial ryegrass ligule
perennial ryegrass vernation
perennial ryegrass ligule
Seedhead / Flower spikea spike, with flattened spikelets along each stem
Vernation Type foldedleaves folded in the bud
Ligule Type membranouscollar-like to blunt, may be toothed near top, 0.02 - 0.06 inches (0.5 - 1.5 mm) long
Growth Season / Life Cycle cool season turf OR perennial weed 
Auricle Type rudimentary 
Leaf Blade Tip Shape sharp-pointedbright green, sharply creased, deeply ridged upper surface, lower surface smooth and glossy, edges slightly rough
Leaf Blade Width narrow, less than 0.1 in OR medium, 0.1 - 0.2 in0.08 - 0.2 inches (2 - 5 mm) wide
Stolon Presence absent 
Rhizome Presence absent 
Collar Type divideddivided by midrib, not hairy, distinct
Sheath Margin   
Sheath Type flattenedsheath is usually flattened, reddish at base