Buttercup family (Ranunculaceae)
Description: This perennial plant is about ½' tall when it blooms, but it later becomes ¾–1¼' tall. It consists of several basal leaves and one or more flowering stalks that develop at about the same time during the spring. The basal leaves are 1-3" long and similarly across; they are palmately divided into dichotomously branched linear lobes. These lobes are 1-3 mm. across; a few coarse teeth may occur along their margins. The basal leaves are medium green and hairless to sparsely hairy above, while below they are densely covered with long silky hairs. The petioles of basal leaves are 1-4" long and densely hairy. Each flowering stalk is light to medium green, terete, relatively stout, and densely hairy. Near the middle of its length, there is a whorl of 3 leafy bracts that are sessile or nearly so. These leafy bracts are about 1-2" long and similarly across; they are similar in appearance to the basal leaves. Each stalk terminates in a single flower that becomes more or less erect when it is fully open.
Each flower is 2-3" across, consisting of 5-8 petaloid sepals, a ring of numerous yellow stamens, and a compound pistil with numerous styles. There are no true petals. The sepals are pale purple to purple, hairy along their outer surfaces, and ovate-oblong in shape. The slender styles form a narrowly ovoid to globoid cluster in the center of the flower; they are yellow or purple. The blooming period occurs from early to mid-spring, lasting about 2 weeks for a colony of plants. Individual flowers are short-lived; they usually bloom during spring days that are sunny and warm. After shedding their sepals, the styles of the flowers become elongated and plumose (feathery); mature styles are ¾–1½" long. At the base of each mature style, there is a flattened achene about 3-4 mm. in length. Because of their plumose styles, these achenes can be blown about by the wind. The root system consists of a woody taproot that can become swollen into a caudex on older plants. This plant spreads by reseeding itself.
Cultivation: The preference is full sun, dry-mesic to dry conditions, and a gritty soil containing gravel or rocky material. The root system may rot if the soil becomes waterlogged from poor drainage. Open areas with scant ground vegetation are preferred as this reduces competition from other plants.
Range & Habitat: Pasque Flower is an uncommon plant that occurs only in northern Illinois (see Distribution Map), where it is native. It has been exterminated from many areas because of modern development. Pasque Flower is native to both North America and Eurasia. In North America, Illinois lies along the SE range limit of this species. The Eurasian variety of this plant is referred to as Anemone patens patens, while the North American variety is referred to as Anemone patens multifida. Habitats include hill prairies, gravel prairies, and rocky bluffs with sparse vegetation. In Illinois, Pasque Flower is found in high quality natural areas. Because of the showy spring flowers, it is also cultivated in flower gardens.
Faunal Associations: The flowers are cross-pollinated by bees, including honeybees, bumblebees, Andrenid bees (Andrena spp.), and Halictid bees (Agapostemon texanus, Halictus rubicundus). The bees collect pollen for their larvae. Syrphid flies also visit the flowers to feed on the pollen, but they are too small to be effective pollinators (Bock & Peterson, 1975; Krombein et al., 1979; Moure & Hurd, 1987). Because the foliage of this plant contains a blistering agent that can irritate the mouth parts and gastrointestinal tract of mammalian herbivores, it is normally avoided by them.
Photographic Location: A flower garden in Urbana, Illinois.
Comments: Pasque Flower is one of the earliest flowers to bloom in a prairie. The common name refers to the religious holiday of Easter, when the flowers are often in bloom. A scientific synonym of this species is Pulsatilla patens, and another common name is Prairie Crocus. Pasque Flower is easy to identify because of its large early-blooming flowers, narrowly lobed leaves, and abundant silky hairs on the foliage and outer surfaces of the sepals. These abundant hairs probably protect the Pasque Flower from spring frosts and various herbivores. The flowers of this plant are larger in size than other anemone species (Anemone spp.) in Illinois. Like many clematis vines (Clematis spp.), it is somewhat unusual in having persistent plumose styles on its achenes.