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.