Description: This native perennial grass develops a
culm during the spring that becomes 1-2' tall by early summer. This ascending
to erect culm is unbranched, or it may have 1-2 short side branches. The culm
is green or purplish green, glabrous or slightly hairy, terete, and partially
hidden by the sheaths. There are 4-6 alternate leaves along its length. The
leaf blades are up to 3½" long and ½" across (or a little more);
they are
dull green, flat, and ciliate along their margins. The upper and lower surfaces
of each blade are hairless to sparsely hairy; if hairs are present, they are
long and spreading. The leaf sheaths are green, purplish green, or purple; they
are strongly veined and more or less covered with long spreading hairs. The
base of each hair is swollen (papillose). Each sheath has a V-shaped opening at
the apex, while at the bottom it is swollen with a ring of hairs. The nodes are
swollen, purplish, and more or less hairy. At the junction of the blade and
sheath, each ligule consists of a narrow ring of fine hairs. Each culm
terminates in a panicle of spikelets about 2½" long and 1½"
across on a short stalk up to 1" long. The branches of this panicle are wiry
and ascending. Sometimes a small tuft of hair occurs where the branches
diverge. The spikelets are 3-4 mm. long and 2.0-2.7 mm. across (about 1.5 times
as long as they are across); they are green to reddish green and glabrous to
sparsely hairy. Each spikelet consists of a small glume, a large glume, and a
lemma that encloses the developing ovary. The small glume is about 1/3 the
length of the spikelet, while the large glume and lemma are the same length as
the spikelet. The blooming period occurs from late spring to mid-summer. The
florets of the spikelets have short plumose stigmas that are purplish and
wind-pollinated. Each mature spikelet produces a single grain about 3 mm. long
and 2 mm. across; the grain is ovoid-obovoid in shape and slightly flattened on
one side. Autumnal culms develop after the spring culms die down. The autumnal
culms are more branched and closer to the ground. The root system is fibrous.
This plant spreads by reseeding itself.
Cultivation: Full to partial sun and mesic to dry
conditions are preferred. This grass adapts readily to soil that is loamy,
sandy, or rocky.
Range &
Habitat: Scribner's Panic Grass is widely distributed and occasional
throughout Illinois (see
Distribution
Map). Habitats include black soil prairies and sand prairies, savannas and
sandy savannas, open rocky woodlands, limestone glades, remnant prairies along
railroads, and abandoned fields. Because this short grass develops during the
cool weather of spring and fall, it is able to avoid direct competition with
the warm-season prairie grasses. 
Faunal
Associations: Various insects feed on Scribner's Panic Grass and
other Panicum/Dichanthelium spp. (Panic Grasses). Several species of
grasshoppers have been found to feed on Scribner's Panic Grass specifically
(see Grasshopper
Table). Other insects that feed on this and other Panic grasses include the
larvae of skippers and moths, leaf beetles, leafhoppers, aphids, stilt bugs,
and stinkbugs (see the Insect
Table for a listing of these species). The seeds of Panic Grasses in mesic
to dry habitats are an important source of food to many upland gamebirds and
granivorous songbirds (see the Bird Table for a listing of these species). Such small rodents
as the Prairie Deer Mouse and House Mouse also eat the seeds. The Cottontail
Rabbit occasionally eats the foliage of Panic Grasses (particularly the shorter
species); the foliage is also edible to bison, horses, and
livestock.
Photographic Location: A
small remnant prairie along a railroad near Champaign,
Illinois.
Comments: This grass
should be used more often in ecological restorations because it is slowly
disappearing with the original tallgrass prairie and savannas. It is a short
attractive grass with unusually wide blades and large seeds. Other scientific
names of this species are Panicum scribnerianum and Panicum
oligosanthes scribnerianum, but it has been reassigned to the
Dichanthelium genus. There are different varieties of Dichanthelium
oligosanthes in Illinois and they are often difficult to distinguish. The
typical variety is more likely to have appressed hairs on its leaves, rather
than long spreading hairs, and its spikelets/grains are about 1.8 times as long
as they are across. In contrast, var. scribnerianum (described above)
often has long spreading hairs on its leaves, and its spikelets/grains are
about 1.5 times as long as they are across. Finally, var. helleri
differs from the preceding two varieties by having smaller spikelets (about 2.5
mm. long and 1.5 mm. across). This variety has been collected only once in
southern Illinois. There are many other Dichanthelium spp. in the state,
but they tend to have smaller spikelets and grains, or their leaf blades are
more narrow (1/3" across or less).