This perennial grass consists of a tuft of leafy culms about ¾–1¾'
long. Normally, these culms are erect or ascending, but in some
situations they have a tendency to sprawl. The culms are light green,
broadly elliptic in cross-section, and glabrous, except near their
nodes, where they are short-pubescent. Occasionally, the culms branch
from the axils of the leaves. Alternate leaves occur along the lower
two-thirds of each culm. The leaf blades are 2-5" long and 1-2 mm.
across, tapering gradually to long slender tips; they are light-medium
green, flat or slightly rolled upward, and glabrous or nearly so. The
margins of these blades are slightly scabrous (rough-textured). The
leaf sheaths are light green, minutely pubescent to short-pubescent,
somewhat flattened, and open; they tend to be more pubescent near the
nodes of the culms. The nodes are slightly swollen, narrowly
ring-shaped, and glabrous to sparsely short-pubescent. The narrow
ligules are about 1 mm. across and short-membranous.
Each fertile culm
terminates in a narrow panicle of spikelets about 3-5" long and less
than ¼" across; this panicle has a spike-like appearance and it is
straight to slightly arching. While immature, the panicle of spikelets
is shiny light green, but it later becomes light tan at maturity. Along
the rachis (central stalk) of each panicle, there are several secondary
branches up to 1¼" long that are erect or appressed. These secondary
branches are usually solitary, rather than occurring in whorls of 2 or
Near the bases of these secondary branches, there are solitary
pedicellate spikelets, while one or more pedicellate spikelets occur
toward their tips. The pedicels of these spikelets are up to 3 mm.
long. The central rachis, secondary branches, and pedicels are
light-medium green, slender, and slightly scabrous. Each spikelet is
about 3 mm. long, narrowly lanceoloid in shape, and somewhat flattened;
it consists of a pair of glumes, a fertile lemma, a palea, and a
perfect floret with 2 stigmas and 3 stamens.
The glumes are 1.5–2.5 mm.
long, lanceolate in shape, membranous along their margins, and slightly
keeled; one glume is slightly longer than the other. The lemma is about
3 mm. long, otherwise it is similar to the glumes. Both the glumes and
lemma are glabrous to minutely pubescent. The small stigmas are plumose
(feathery) and reddish purple. The blooming period occurs from late
summer to early autumn; individual florets remain in bloom for about 1
week. The florets are cross-pollinated by the wind. Afterwards, the
fertile florets of spikelets are replaced by grains. These grains are
about 2 mm. long, narrowly ellipsoid in shape, light tan, and somewhat
flattened; they are light enough to be blown about by the wind to some
extent. The root system consists of a crown of fibrous roots.
This grass prefers full sun, dry conditions, and a relatively heavy
sterile soil containing clay and/or stony material. It is able to
tolerate partial sun and soil that is more moist and fertile, although
its leafy culms have a tendency to sprawl under these conditions.
Growth and development occur slowly and steadily during the summer, and
resistance to drought is good. Prairie Satin Grass could be used as an
ornamental grass in rock gardens that are sunny and dry.
Grass occurs in widely scattered areas of NE and western Illinois,
where it is native and rare (see Distribution
). Most populations of this grass within the
state have been found relatively recently. Illinois lies along the SE
range limit of this grass, which is more common in the northern plains
region of the United States and adjacent areas of Canada. In Illinois,
habitats include hill prairies, upland gravel prairies, upland dolomite
prairies, rocky bluffs, limestone glades, long sloping banks of major
rivers, and grassy fens (this last habitat is atypical). In Illinois,
Prairie Satin Grass is a conservative species that is found in sunny
upland areas where some of the original ground flora remains intact
from disturbance (e.g., grazing from cattle).
Prairie Satin Grass (Muhlenbergia cuspidata
the host, or probable host, of several oligophagous or monophagous
leafhoppers, including Flexamia
(Hamilton & Whitcomb, 2010; Whitcomb & Hicks, 1988).
However, these leafhoppers are distributed primarily in areas that lie
NW of Illinois, where Prairie Satin Grass is more common. Among
vertebrate animals, the Wild Turkey feeds on the seeds, while such
hoofed mammalian herbivores as the Elk, White-tailed Deer, and
domesticated cattle browse on the foliage to a greater or less extent,
depending on the geographic location (Fry, 2009).
The wildflower garden of the webmaster in
Prairie Satin Grass (Muhlenbergia
) has very slender stems and leaves, and its
inflorescence is narrow and spike-like. Although it has an appearance
that is rather
insubstantial and ethereal, this grass is tougher than it looks.
Compared to other similar
(Satin Grasses) in Illinois, Prairie Satin Grass can be distinguished
by its somewhat flattened stems, narrow
leaf blades (1-2 mm. across), spike-like inflorescence, awnless
spikelets, and lack of rhizomes. Like many true prairie grasses, it is
a bunchgrass, rather than a sodgrass. The bunchgrass habit is the
result of an expanding crown of fibrous roots as this perennial grass
ages. Another common name of this grass is Plains Muhly.