Description:
This native perennial grass is 2½–5' tall and little branched. The
erect central culm is green and terete (round in cross-section). The blades of
the alternate leaves are up to 12" long and 2/3" across; they are greyish green
to dark green, hairless, and rather floppy. The leaf sheaths are greyish green,
finely ribbed, hairless, and sometimes glaucous. The ligule at the junction of
the sheath and blade has a short papery membrane that eventually turns brown.
The nodes are swollen and often whitened. The central culm terminates in a
floral spike about 5-9" long; this spike is more or less erect. Pairs of
spikelets occur sparingly along the spike; during the blooming period, they are
perpendicular to the central stalk (or rachis) of the spike and widely
spreading. Each spikelet has 2-4 florets. Usually, there are no glumes,
although sometimes the lowest spikelets have glumes that are reduced to
bristles up to 2/3" long. The lemmas are about ½" long and their
straight awns are ½–1½" long. Each lemma is
lanceolate-linear, greyish green, and convex on the outer surface. The florets
of the lemmas have 3 white anthers and a pair of plumose stigmas. In the
typical variety of Bottlebrush Grass, the lemmas are hairless, however var.
bigeloviana has pubescent lemmas. The blooming period occurs during the
summer. Pollination is by wind. The spikelets easily detach from the central
stalk of the inflorescence and fall to the ground; they become straw-colored
with maturity. The seeds are long and narrow. The root system is fibrous. This
grass spreads primarily by reseeding itself; it often forms small colonies of
several plants.
Cultivation: The
preference is partial sunlight to light shade, moist to slightly dry
conditions, and soil that is loamy or rocky.
Range & Habitat: The typical variety of
Bottlebrush Grass occurs in every county of Illinois and is fairly common;
var. bigeloviana is widely scattered across the state and apparently
much less common (see the
Distribution
Map for this latter variety). Habitats of both varieties include mesic
deciduous woodlands, rocky upland woodlands, woodland openings, woodland
borders, areas along woodland paths, meadows in
wooded areas,
savannas, and rocky glades. Bottlebrush Grass is usually found in fairly high
quality woodlands and adjacent areas. Sometimes this species is grown as an
ornamental grass in gardens; it is often used in savanna
restorations.
Faunal Associations:
The caterpillars of the butterfly Enodia anthedon (Northern Pearly Eye)
feed on Bottlebrush Grass, as do the caterpillars of the moths Cosmiotes
illectella (a leaf-miner moth), and Leucania pseudargyria (False
Wainscot). The caterpillars of the latter moth transfer to other species of
plants when they become larger. The awned spikelets of mature plants can cause
mechanical injury to livestock, otherwise the foliage is edible.
Photographic Location: A mesic
deciduous woodland at Busey Woods in Urbana, Illinois. The photographs show
Elymus hystrix bigeloviana, which has pubescent lemmas.
Comments: This native grass has a distinctive
inflorescence and attractive appearance. The bottlebrush-shape of the floral
spike makes it easy to identify. The spikelets of other Elymus spp.
(Wild Ryes) are less remote from each other and more erect along the central
stalk of their floral spikes. Other Wild Ryes also have a pair of long glumes
at the base of each of their spikelets, while the spikelets of Bottlebrush
Grass usually lack such glumes (or they have been reduced to bristles). Because
of these structural differences, Bottlebrush Grass is sometimes assigned to a
different genus and referred to as Hystrix patula. However, it is
sufficiently similar to other species of Wild Rye to form hybrids with them
(particularly with Elymus virginicus). These hybrids display
characteristics of both parents; they can be found occasionally in natural
areas.