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 and will grow readily in soil that is loamy, sandy, gravelly, or full of clay. It is an easy 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.
HABITAT: 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.
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. Found throughout the Tallgrass Region on mesic to dry prairies. Yellow flowers up to 2 inches across, rays have a notch at the tip, blooms from June through July.