Description: This native perennial grass is 2-3'
tall and tufted at the base. The culms are tan or reddish brown, hairless, and
terete; the base of each culm is erect, rather than decumbent across the
ground. Alternate leaves are produced primarily along the lower half of each
culm. The leaf blades are up to 10"
long and ¼" across, light green or
light blue, hairless or slightly pubescent, and curling outward. The leaf
sheaths are light green or light blue, hairless or slightly pubescent, and
finely ribbed. Each culm terminates in several ascending racemes of spikelets.
Each raceme is about 1½–3" long and it has a peduncle (or flowering
stalk) of variable length underneath. Several pairs of spikelets occur on
opposite sides of the raceme's rachis (central stem); this rachis is covered
with long white hairs and it tends to zigzag between the spikelets as they
become mature. For each pair, there is a fertile spikelet that is sessile and a
sterile spikelet on a slender pedicel. The fertile spikelet is about ¼"
(6 mm.) in length (excluding any awns); it consists of a pair of outer glumes
and a pair of inner lemmas. The narrow glumes are light green to tan and
hairless or slightly hairy. The fertile lemma is tan to reddish brown and it
has a slender white awn about 1/3" (10 mm.) at its apex; this awn can be
straight to strongly curved. The sterile spikelet is about one-half the length
of the fertile spikelet and it also has a slender white awn. The florets have
anthers that are brown or reddish brown and plumose stigmas that are pale
purple. The blooming period occurs from late summer into the fall. Each fertile
spikelet produces a single elongated grain. The root system is fibrous and
rhizomatous. Tight bunches of culms and leaves are produced from the short
rhizomes. The culms and leaves become various shades of tan, brown, or wine-red
during the fall and winter.
Cultivation: The preference is full sun and mesic to
dry conditions. Different kinds of soil are tolerated, including those that
contain clay-loam, gravel, or sand. Less fertile soil is preferred because of
the reduced competition from taller vegetation. Because of its C4 metabolism,
Little Bluestem develops primarily during the warm weather of summer and early
fall, and it has excellent drought resistance.
Range & Habitat: Little Bluestem is occasional
to locally common in most areas of Illinois, although voucher specimens haven't
been collected in some counties (see
Distribution
Map). Habitats include hill prairies, gravel prairies, sand prairies, black
soil prairies, clay prairies, scrubby barrens, rocky slopes of thinly wooded
bluffs, sandy savannas, hilltop glades (limestone, sandstone, or shale), sand
dunes, gravelly areas along railroads, and abandoned fields. Little Bluestem is
often used in prairie restorations and it is occasionally found in gardens as
an ornamental grass. In Illinois, this is one of the dominant grasses of hill
prairies.
Faunal
Associations: The caterpillars of several skippers feed on the
leaves, including Atrytonopsis hianna (Dusted Skipper), Hesperia
leonardus (Leonard's Skipper), Hesperia metea (Cobweb Skipper),
Hesperia ottoe (Ottoe Skipper), Hesperia sassacus (Indian
Skipper), Nastra lherminier (Swarthy Skipper), and Polites
origenes (Crossline Skipper). A skipper looks like a cross between a small
moth and a small butterfly. This insect is common in prairies where Little
Bluestem and other grasses occur. Many grasshoppers feed on the foliage (see
Grasshopper Table);
they are common in prairies and an important food source for many birds. Other
insects that feed on Little Bluestem and closely related Andropogon spp.
(Beard Grasses) include several oligolectic spittlebugs, leafhoppers, thrips,
and beetles, including Prosapia ignipectus (Black Spittlebug),
Flexamia delongi (Leafhopper sp.), Laevicephalus unicoloratus
(Leafhopper sp.), Illinothrips rossi (Thrips sp.), and Aniostena
nigrita (Leaf-Miner Beetle sp.). The Field Sparrow, Tree Sparrow,
Slate-Colored Junco, and other small songbirds eat the seeds, particularly
during the winter. The foliage of Little Bluestem is quite palatable to bison,
cattle, and other hoofed mammalian herbivores.
Photographic Location: The wildflower garden of the
webmaster in Urbana, Illinois.
Comments: Little Bluestem is an attractive prairie
grass, particularly during the fall. While the stems of other grasses become
matted during the winter, the stems of Little Bluestem remain conspicuously
upright. This species is somewhat variable in the appearance of its foliage and
the hairiness of its floral racemes. Glaucous forms with blue summer foliage
can be found in dry gravelly areas along railroads, while forms with reddish
fall foliage are often cultivated. An older scientific name for this species is
Andropogon scoparius. However, the floral racemes of Little Bluestem
occur individually on slender stalks, while the floral racemes of Andropogon
spp. (Beard Grasses) occur in groups (often in finger-like clusters from
the same stalk). This is the only Schizachyrium sp. in Illinois,
although other species in this genus can be found in southeastern or
southwestern areas of the United States. They differ from Little Bluestem in
having racemes with longer hairs (at least ½" in length) and culms that
are partially decumbent on the ground.