Lolium perenne

(aka Festuca perennis)


Perennial Ryegrass


Field view of Lolium perenne or Perennial Ryegrass

Field view of Lolium perenne, common name Perennial Ryegrass. It is sometimes annual.

 Perennial Ryegrass Spike

The newer name, Festuca perennis, or Annual Ryegrass (also called Italian Ryegrass), is not fully accepted.

 Closer View of Seedhead

Closer view. Unike similar spiked wheat and rye grasses, the spikelets are in the same plane as the rachis, like open hands.

Front and Side Views

On the left you see the open hands. Turn it sideways and the spikelets are on edge.

 The Inflorescence Is Spiked

Another view of the spiked inflorescence. The spikelets alternate on either side of the rachis.

 Spikelet with Shadow

The shadow shows the flat faces while the actual spike is on its side.

Roots of Perennial Ryegrass

The roots may be sparce or deep depending on how annual or perennial the individual plant.

 More Roots

More root examples.

 Wide Leaves of Annual Ryegrass

This shows the wider and more lax leaves of the annual variety.

Spikelets Face Outward

This shows the outward-facing spikelets. Some plants have awns, some do not.

 Individual Spikelets with Awns

The awnless variety.

 Close View of One Spiklet

There are about ten florets on this annual variety. The delicate white stigmas are visible.


How to Identify Perennial Ryegrass

  Lolium perenne is a short-lived perennial or annual bunchgrass whose seedheads are true spikes. It is usually up to knee-high but can grow to hip high. It is one of the most common lawn grasses. It has an unusual way of displaying its spikelets: they are in the same plane as the stem, like open hands facing outward.

  There is a subspecies that is sometimes called a species, Lolium multiflorum (Annual Ryegrass), which varies from Perennial Ryegrass in having wider leaves that are more lax, and it is more often awned. Conflicting names are in circulation, especially Festuca perennis, which is not accepted by all international experts. While they duke it out, I am retaining the name Lolium perenne var. multiflorum.


Similar Species

   Lolium perenne (Perennial Ryegrass) and Lolium multiflorum (Annual Ryegrass) are very similar. The annual variety is usually shorter-lived and has wider leaves and more abundant florets, over 10 in each spikelet, though this is disputed. For now I recommend calling both of these Perennial Ryegrass.