Poverty Oat Grass
Grass family (Poaceae)
Description: This 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 1-2' 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 ¾–2" long. This inflorescence is either a raceme or narrow panicle of floral spikelets; the latter is raceme-like in appearance. The branches of the inflorescence are short, slender, and ascending to erect; the spikelets are few in number.
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-lanceolate in shape; they are mostly green with white-membranous margins. The lemmas are arranged in 2 overlapping ranks; they are 3.5–5.0 mm. long, and elliptic. The outer surfaces of the lemmas are gently curved (convex) and covered with fine white hairs. Each lemma terminates in a pair of tiny teeth and a central awn that is 5-8 mm. in length; the latter is often twisted or coiled near the base. The blooming period occurs from late spring to mid-summer, lasting about 2 weeks for a colony of plants. The perfect florets are cross-pollinated by the wind. 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: The native Poverty Oat Grass is occasional in most areas of Illinois, except the NW section, where it is uncommon (see Distribution Map). 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, tops of rocky embankments, 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 the caterpillars of Hesperia leonardus (Leonard's Skipper), the caterpillars of Hesperia sassacus (Indian Skipper), Chloealtis conspersa (Sprinkled Grasshopper), Chortophaga viridifasciata (Green-Striped Grasshopper), Orphulella speciosa (Slant-faced Pasture Grasshopper), the larvae of Calamomyia danthoniae (Oat Grass Midge), 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, edge of a rocky embankment at the Pine Hills State Nature Reserve in west-central Indiana, and edge of a lawn at a nature lodge in Pope County, Illinois.
Comments: This is the only grass of this genus in Illinois; other Danthonia spp. can be found in more western and southern areas of the United States. Unlike Poverty Oat Grass, these other species have lemmas with pairs of short lateral awns (in addition to the central awns), instead of lemmas with pairs of tiny teeth. Because of its dense tufts of curly basal leaves, Poverty Oat Grass is distinctive in appearance and relatively easy to identify, even when it isn't in bloom. However, because of its diminutive size, this grass species can be overlooked. Another common name is Curly Grass.