Description: This native perennial grass is tufted at the base, sending out multiple culms that are erect to spreading and up to 2½' long. The culms are green to reddish green and terete, branching occasionally to produce side stems. Each node of the culms has a dense ring of long white hairs; sometimes the culms are reddish near the nodes. The blades of the alternate leaves are up to 3½" long and nearly ½" across; they are narrowly lanceolate, green, and flat. The upper surface of each leaf blade is hairless or sparsely covered with short white hairs; sometimes there are a few long hairs near its base. The lower surface of each leaf blade is more or less hairy. The leaf sheaths are green, longitudinally ribbed, and heavily covered with long white hairs.
Each culm terminates in a panicle of
spikelets up to 4" long and about half as broad. The central stalk of the
panicle has long spreading hairs, particularly in the lower half. The slender
branches of the panicle are usually glabrous, slightly curly, and spreading to
ascending. These branches terminate in one-flowered spikelets about
1.5–2.0 mm. long. These spikelets are green to purple, conspicuously
pubescent, and ovoid to obovoid in shape; they later become tan. The smaller
glumes are about 1/4 to 1/3 the length of the spikelets, while the lemmas and
larger glumes are about the same length as the spikelets. The side stems of the
culms often terminate in panicles of florets as well, although they are smaller
in size. The primary blooming period typically occurs during early summer.
After this vernal phase of development, this grass, like other Dichanthelium
spp., dies down during mid-summer to late summer. During the autumnal phase
of development, this grass regenerates itself and forms a low rosette of
spreading culms and leaves. Sometimes panicles of spikelets are formed, and a
second blooming period may occur during the fall. Each spikelet produces a
single grain about 1.5 mm. long that is somewhat flattened and tapered at both
ends. The root system is fibrous. This grass spreads by reseeding
itself.
Cultivation: The preference
is light shade to full sun and moist to dry conditions. Different kinds of soil
are tolerated, including those containing loam, clay-loam, rocky material, and
sand. This grass has a tendency to die out if it competes with taller ground
vegetation.
Range &
Habitat: Woolly Panic Grass is common and can be found in all
counties of Illinois (see
Distribution
Map). Habitats include openings in upland woodlands and sandy woodlands,
typical savannas and sandy savannas, disturbed meadows in wooded areas,
disturbed areas of mesic to dry prairies, sandstone glades, thinly wooded rocky
bluffs, powerline clearances in wooded areas, and old fields. Less often, this
grass can be found in open wetland areas, such as sandflats, but this is
unusual. This species prefers disturbed areas with reduced ground vegetation
and it has low fidelity to any particular habitat.
Faunal Associations: The caterpillars of several
skippers feed on the foliage of Panicum spp. and Dicanthelium
spp. (both Panic Grasses), including Hesperia sassacus (Indian
Skipper), Poanes hobomok (Hobomok Skipper), Polites themistocles
(Tawny-Edged Skipper), and Wallengrenia egremet (Northern Broken-Dash).
Other insect species that are oligoleges of Panic Grasses include Polyamia
rossi (Leafhopper sp.) and Cycloplasis panicifoliella (Heliodinid
Moth sp.). The seeds of Panic Grasses are an important source of food to many
birds, particularly upland gamebirds and granivorous songbirds (see the
Bird Table for a listing of
these species). Panic Grasses are eaten occasionally by the Cottontail Rabbit
and hoofed herbivores (primarily livestock); the foliage of these grasses is
palatable while it is young.
Photographic
Location: A powerline clearance at Busey Woods in Urbana,
Illinois.
Comments: This is one of
the more common Dicanthelium spp. in Illinois. It used to be referred to
as Panicum lanuginosum fasciculatum, however the shorter Panic Grasses
have been separated into their own genus. These Panic Grasses bloom during the
late spring or early summer, die down during mid- to late summer, and develop
low rosettes during the fall, at which time they may bloom again. Those grasses
remaining in the Panicum genus tend to be taller warm-season grasses
that bloom from mid-summer to the early fall, after which they die down and
become dormant during the winter. There are several varieties of Woolly Panic
Grass that are difficult to distinguish and sometimes intergrade in the
field; var. fasciculatum, as described above, is the most common variety
in Illinois. Woolly Panic Grass can be identified by its pubescent spikelets,
the hairiness of the lower central stalk in the inflorescence, and the length
of its spikelets (1.5–2.0 mm.). Other Panic Grasses have hairless
spikelets, a hairless central stalk in the inflorescence, and spikelets that
are either longer or shorter. Sometimes the relative hairiness of the sheaths
and leaf blades (both upper and lower surfaces) helps to distinguish different
varieties or species of Panic Grasses.