This perennial grass is 2½-4' tall, consisting of a loose tuft of leafy
culms that are more or less erect. About 4-7 alternate leaves occur
along the lower half of each culm. Individual culms are
rather terete, hollow, light green, unbranched, and either
glabrous or sparsely short-pubescent; they are mostly hidden by the
sheaths. The leaf blades are up to 12" long and 15 mm. across; they are
rather floppy and widely spreading. The upper blade surface is medium
to dark green, slightly shiny, and either glabrous
or short-pubescent The lower blade surface is medium to dark
green, rather dull, and either glabrous or short-pubescent. The sheaths
are green to blue-green and either glabrous, short-pubescent, or
hairy; they are closed, except for V-shaped openings at their apices.
The nodes are slightly swollen, dark green, and either glabrous or
hairy. The ligules are short-membranous.
Each fertile culm terminates
in a panicle of drooping spikelets about 4-12" long and similarly
across; the panicle may have a balanced pyramidal shape or it may
droop to one side. Along the central rachis of the panicle, there are
whorls of 2-4 lateral branches that divide into branchlets; the rachis,
branches, and branchlets are medium to dark green, very slender, and
drooping from the weight of the spikelets. The spikelets are 2-3
cm. in length, 4-5 mm. across, and somewhat flattened; immature
spikelets are light green or gray-green, while mature spikelets become
brown. Each spikelet has a pair of glumes at the bottom and 5-11 awned
lemmas that are arranged above into two ranks. The smaller glume is 6-8
long, linear in shape, and single-veined, while the larger glume is
8-10 mm. long, linear-lanceolate in shape, and 3-veined. Both glumes
are either glabrous or sparsely short-pubescent and their outer
surfaces are convex, rather than keeled. The lemmas are 8-12 mm. in
length (excluding their awns), narrowly oblong-elliptic in
shape, 5-veined, and convex along their outer surfaces. The lemmas
are usually short-pubescent along the entire length of their outer
surfaces, sometimes with longer hairs along their margins. On rare
occasions, the lemmas are glabrous. The awns of the lemmas are 3-6 mm.
in length and straight. Each fertile lemma has a floret with a pair of
feathery stigmata, 2-3 anthers, and a developing ovary. The
blooming period occurs from late spring to mid-summer,
lasting about 1-2 weeks. The florets are wind-pollinated. Afterwards,
the lemmas disarticulate from the spikelets above the glumes,
dispersing their elongated grains. The root system is fibrous.
This grass prefers partial sun to light shade, moist to mesic
conditions, and soil containing fertile loam, silt-loam, or sandy loam.
It is one of the taller grasses with some tolerance of shade.
The native Hairy Woodland Brome is
throughout Illinois (see Distribution
). Habitats include rich mesic
woodlands, woodlands and savannas along rivers, disturbed open
woodlands, thickets, woodland borders, and edges of swamps. This grass
is usually found in bottomland or floodplain areas where various
deciduous trees are dominant. It is rarely found in open areas.
Insects that feed on woodland brome grasses
documented, but they may include the following two species: leaf-mining
larvae of the leaf beetle, Chalepus
, and leaf-mining larvae of
the moth, Elachista
. Some vertebrate animals that feed on
the seeds of these grasses include the Ruffed Grouse, Wild Turkey,
various sparrows, and the White-Footed Mouse. Vertebrate animals that
feed on the foliage include the White-Tailed Deer (during fall
winter) and Cottontail Rabbit (young foliage). The foliage is also
palatable to domesticated farm animals (cattle, horses, etc.) when it
is young. There is also a record that lists brome grass as a food plant
of the Eastern Box Turtle (Ernst et al., 1994), which is found in
habitats that are similar to Hairy Woodland Brome.
Edge of a bottomland woodland at the Indiana
Lakeshore in NW Indiana.
This is a tall lanky grass with drooping spikelets and the most common
native brome grass in Illinois. The hairiness of individual plants is
variable across local populations. The taxonomic history of this
species has been unstable; this grass has been referred to as Bromus
in the past. Hairy Woodland Brome is very
similar to Fringed Woodland Brome (Bromus
) and Leafy Woodland
Brome (Bromus purgans
These are all native species that occupy
similar habitats. Fringed Woodland Brome can be distinguished by its
lemmas, which have hairs along the lower two-thirds of their margins,
otherwise its lemmas are glabrous. Leafy Woodland Brome can be
distinguished from the preceding two species by the abundance of leaves
along its culms (typically 9-15 per culm). It is also possible to
encounter plants that display mixed characteristics of the
preceding species. Such plants may be naturally occurring hybrids.