Grass family (Poaceae)
Description: This native perennial plant is 1½3½' tall and unbranched or little branched. The slender culm is light green, hairless, and round in cross-section. The blades of the alternate leaves are up to 10" long and 1" across; they are linear-lanceolate, light green, flat, and mostly hairless. However, there is often a small tuft of white hairs at the base of the leaf blade near the ligule. The sheaths of the leaves are light green and hairless. The culm terminates in a panicle of spikelets about 4-12" long and half as much across; pedicels of the spikelets are very slender and nodding. Each spikelet is about 1" long and 1/3" across; it is flattened, light green, and mostly hairless. Sometimes the spikelets are tinted light purple toward their margins and at the tips of their lemmas. Each spikelet consists of 2 glumes and several pairs of lemmas. The glumes at the base of the spikelet are linear in shape and keeled, while the lemmas are linear-lanceolate and keeled. The lemmas are about 1/3" long and slightly longer than the glumes. The lower lemmas are often sterile. Each flower has a single stamen. The spikelets turn brown at maturity and eventually disarticulate above the glumes. The blooming period occurs from mid-summer to early fall. The root system produces rhizomes, and vegetative colonies are sometimes formed.
Cultivation: The preference is partial sun, moist conditions, and a fertile loamy soil. Plants tend to be smaller in areas that are drier and less fertile.
Range & Habitat: Inland Oats is common in the southern half of Illinois, but uncommon or absent in the northern half of the state (see Distribution Map). This is primarily a southern species as Illinois lies along the northern portion of its range. Habitats include moist alluvial meadows, rocky slopes along streams, limestone glades, thinly wooded areas in river floodplains, moist woodlands, and woodland borders. Some local populations may derive from plants that have escaped cultivation.
Faunal Associations: The flowers attract few insects because they are wind-pollinated. The caterpillars of the butterfly Enodia anthedon (Northern Pearly Eye) feed on the foliage of Inland Oats, as do the caterpillars of several Amblyscirtes spp. (Roadside Skippers), including Amblyscirtes vialis (Common Roadside Skipper), Amblyscirtes linda (Linda's Roadside Skipper), and Amblyscirtes belli (Bell's Roadside Skipper). The latter two skippers are restricted to southern Illinois and neighboring areas, where their preferred food plant, Inland Oats, is more common.
Photographic Location: Along the rocky edge of a pond in a city park at Champaign, Illinois.
Comments: This attractive grass is often cultivated in gardens and the branches of its spikelets can be used in flower arrangements and winter bouquets. Inland Oats is easy to identify because of its large flat spikelets and broad leaves. The nodding spikelets move about on their slender pedicels with each passing breeze. Another scientific name for this plant is Uniola latifolia. It has different common names, including Broad-Leaved Uniola, Wild Oats, and River Oats. The common name 'Sea Oats' is inappropriate as this actually refers to another species, Uniola paniculata, which is not found in Illinois. This latter species occurs primarily along coastal areas that are sandy. It is a taller plant with more erect spikelets; each of its flowers has 3 stamens.