Poverty Oat Grass
Grass family (Poaceae)
Description: This native perennial grass consists of a dense tuft of low basal leaves, from which one or more flowering culms develop. The blades of the basal leaves are up to 2 mm. across and 5" long; they are medium green, hairless, and often curving to the left or the right. Quite often, their margins are involute (rolled inward). Old basal leaves are persistent and tan-colored; they resemble young basal leaves, except they are even more curved and involute. The slender flowering culms are 11½' tall, more or less erect, terete, and hairless. Each culm has about 2 alternate leaves with ascending blades. The blades of the alternate leaves are similar to the basal leaves, except they are more short and straight. The leaf sheaths are green and mostly hairless. However, there is a small tuft of hairs at the apex of each sheath.
Each culm terminates in an inflorescence about ¾2" long. This inflorescence is a panicle of floral spikelets that is narrow and raceme-like in appearance. The branches of the inflorescence are short, slender, and ascending. Individual spikelets are 7-15 mm. long, consisting of a pair of glumes and 3-7 lemmas with their florets. The glumes are 7-15 mm. long, hairless, and linear in shape. The lemmas are arranged in 2 ranks; they are 3.55.0 mm. long, narrowly ovoid, and flattened. The outer surfaces of the lemmas are gently curved and covered with fine hairs. Each lemma terminates in a pair of tiny teeth and a central awn that is 5-8 mm. in length and usually twisted or coiled near the base. The blooming period occurs during early to mid-summer for about 2 weeks; the florets are wind-pollinated. Each lemma of the spikelets contains a single grain. Disarticulation of the spikelets is above the glumes. Poverty Oat Grass also produces cleistogamous (self-fertile) florets. The root system is fibrous and short-rhizomatous.
Cultivation: Full sun to light shade, dry-mesic to dry conditions, and sterile soil containing sand, gravel, or rocky material are preferred. This grass does not tolerate competition from taller ground vegetation.
Range & Habitat: Poverty Oat Grass is occasional in most areas of Illinois, except the NW section, where it is uncommon. Habitats include upland woodlands (usually sandy or rocky), thinly wooded bluffs and slopes, sand prairies, gravel prairies, dolomite prairies, partially shaded edges of hill prairies, limestone and sandstone glades, and overgrazed pastures. In general, this grass prefers dry upland areas where there is scant ground vegetation and few fallen leaves.
Faunal Associations: Various insects feed on the foliage of Poverty Oat Grass. These include Hesperia leonardus (Leonard's Skipper), Hesperia sassacus (Indian Skipper), Chortophaga viridifasciata (Green-Striped Grasshopper), Orphulella speciosa (Slantfaced Pasture Grasshopper), and the leafhopper Laevicephalus melsheimerii. Because of the low growth habitat of the basal leaves and the preponderance of dead leaves, cattle and other hoofed mammalian herbivores graze on the foliage very sparingly.
Photographic Location: Partially shaded edge of a hill prairie in Vermilion County, Illinois. The photograph was taken during the spring, when the blades of young basal leaves were starting to develop.
Comments: This is the only grass of this genus in Illinois; other Danthonia spp. can be found in western and southern areas of the United States. Unlike Poverty Oat Grass, the pairs of small teeth on their lemmas bear short awns (in addition to the central awns). Because of its dense tufts of curly basal leaves, Poverty Oat Grass is relatively easy to identify, even when it is isn't in bloom. However, because of its diminutive size, this grass species can be overlooked. Another common name is Curly Grass.