Description: This native perennial plant is 1-3' tall and unbranched. The central stem is hairless, except for small tufts of hair at the base of the leaves.The opposite leaves are about 2-4" long. They are usually divided into 3 narrow lobes, but are sometimes linear near the inflorescence. The larger central lobe may also be divided into 1 or 2 small narrow lobes. These leaves are medium to dark green, sessile, and hairless. They are distributed evenly along the stem.
The composite flowers are bright yellow
and 1½-2" across. Each composite flower has numerous disk florets, which
are surrounded by about 8 ray florets. The outer edges of the ray florets are
less ragged in appearance than the ray florets of many other species of
coreopsis. The blooming period occurs during early summer, and lasts about 3
weeks. There is no floral scent. The achenes do not have tufts of hairs. The
root system is rhizomatous, and can produce dense colonies of this plant that
exclude other species. During the fall, the foliage often acquires reddish
tints.
Cultivation: The preference
is full sun and mesic to dry conditions. This plant isn't fussy about soil
characteristics, but will grow readily in soil that is loamy, sandy, gravelly,
or full of clay. It is an easy to plant to grow, but may sprawl unless it
receives full sun and rather lean treatment. It can spread aggressively. The
foliage usually remains in good condition until hard frosts during the
fall.
Range & Habitat: Prairie
Coreopsis occurs occasionally in most counties of Illinois, but is rare or
absent in SE Illinois and some western counties (see
Distribution
Map). Habitats include mesic to dry black soil prairies, sand prairies,
gravelly hill prairies, thickets, open areas of rocky upland forests, Black Oak
savannas, limestone glades, and abandoned fields. It is usually found in high
quality habitats because the dispersion of the seeds is rather limited.
Faunal
Associations: The flowers are visited by many kinds of insects,
especially long-tongued bees, short-tongued Halictine bees, and flies. Other
insect visitors include wasps, butterflies, skippers, moths, and beetles. These
insects usually seek nectar from the flowers, although bees often collect
pollen for their larvae and adult beetles eat pollen. The long-tongued bee
Melissodes coreopsis (Coreopsis Miner Bee) is an oligolege of
Coreopsis spp. The caterpillars of the moths Tornos
scolopacinarius (Dimorphic Gray) and Eynchlora acida (Wavy-Lined
Emerald) feed on the foliage of this and other coreopsis species. Mammalian
herbivores occasionally consume the foliage of Prairie Coreopsis, including
rabbits, groundhogs, livestock, and probably deer.
Photographic Location: Photographs were taken at the
webmaster's wildflower garden in Urbana, Illinois.
Comments: This plant has the advantage of flowering
somewhat earlier during the summer than many other prairie wildflowers. It is
more impressive when allowed to form dense colonies. Prairie Coreopsis can be
distinguished from many other species of coreopsis by the less ragged
appearance of its flowers and the characteristics of its foliage. The narrow,
deeply lobed leaves are wider and less thread-like than Coreopsis
grandiflora (Large-Flowered Coreopsis) and Coreopsis verticilliata
(Whorled Coreopsis), which are not native to Illinois. Also, the leaves are
shorter, more deeply lobed, and distributed more evenly along the stem than
Coreopsis lanceolata (Lance-Leaved Coreopsis). Prairie Coreopsis is much
shorter and blooms earlier than Coreopsis tripteris (Tall
Coreopsis).