Description:
This introduced grass is a short-lived perennial that produces a small tuft of
alternate leaves and an erect flowering culm about 8-16" tall. The leaf blades
are about 2-4 mm. across and up to 5" long; they occur along the lower
one-third of fertile culms. The blades are medium green to dark blue-green,
hairless, and rather stiff and straight. The leaf sheaths are arranged tightly
around their culms; they are medium green and hairless. Each fertile culm
terminates in a flowering spike about 4-8" long. This spike consists of several
sessile spikelets that alternate along two sides of the rachis (central stalk
of the spike). The rachis is slightly indented where each spikelet occurs,
providing it with a curvilinear zigzag appearance. Each spikelet is up to 12
mm. (½") long, consisting of a single outer glume at its base and 5-10
overlapping lemmas and their florets. Each lemma is 5-7 mm. in length,
linear-oblong in shape, and gently curved along its outer surface. The glume is
longer than individual lemmas, but shorter than the spikelet. Aside from its
greater length, the glume is similar in appearance to the lemmas. The blooming
period typically occurs during early summer, although this may be delayed by
disturbance. As the lemmas mature, they become silvery green and then
tan-colored. Each fertile lemma produces a single elongated grain. The root
system consists of a tuft of shallow fibrous roots. This grass reproduces
primarily by reseeding itself.
Cultivation: The preference is full or partial sun,
mesic to dry conditions, and soil containing loam or clay-loam. This grass
remains green during hot summer weather, and prefers areas with reduced
competition from other plants. Regular mowing is readily
tolerated.
Range & Habitat: This
common grass has been collected in most counties of Illinois (see
Distribution
Map); it probably occurs in every county within the state. Habitats include
lawns, fallow fields, grassy areas along roadsides and railroads, and open
waste areas. Areas with a history of disturbance are preferred. English Rye
Grass is often cultivated as a lawn grass in conjunction with Poa
pratensis (Kentucky Bluegrass) and other turf grasses. It often escapes
into adjacent areas, including lawns where it wasn't originally
introduced.
Faunal
Associations: Surprisingly little is known about floral-faunal
relationships for this common grass. Two insect species, Oulema
melanopus (Cereal Leaf Beetle) and Chaetocnema pulicaria (Corn Flea
Beetle), feed on the foliage of English Rye Grass; these polyphagous beetles
also feed on many other species of both wild and cultivated grasses. The
foliage is edible to mammalian herbivores, including cattle, sheep, goats, and
horses. English Rye Grass was planted as a pasture grass in Europe before it
was introduced into North America.
Photographic
Location: A lawn in Urbana, Illinois.
Comments: This little grass remains green longer in
the summer than Kentucky Bluegrass (Poa pratensis) and it blooms a little
later. However, the airy inflorescence of Kentucky Bluegrass is very different
from the narrow floral spike of English Rye Grass. Two other introduced
species, Lolium muliflorum (Italian Rye Grass) and Lolium
temulentum (Darnel), are similar in appearance, but they are less common in
Illinois. Italian Rye Grass is larger in size overall, with more lemmas per
spikelet (10-20) that are usually awned. Darnel differs from the preceding
grass species by having glumes that are longer than than its spikelets; these
glumes are ½–¾" long. Because of their distinctive floral
spikes, it is relatively easy to identify these three grasses. They should not
be confused with Elymus spp. (Wild & Cultivated Rye), which are
quite distinct, in spite of the similarity in their common
names.