Grass family (Poaceae)
Description: This native perennial grass is 2½5' 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 ½1½" 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.