Description: This native perennial
plant is 1½–3½' 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.