Poppy family (Papaveraceae)
Description: This native perennial plant is 11½' tall, consisting of basal leaves and a stem that terminates in a small cluster of flowers. This stem is conspicuously hairy and has a pair of opposite leaves. The leaves are up to 6" long and 2½" across. They are double pinnatifid; there are 2-3 pairs of primary lobes along the length of each leaf, while shallow secondary lobes occur along the length of each primary lobe. There are scattered short hairs across the upper surface of each leaf, although they are hard to see.
The petioles of the leaves are rather long and conspicuously hairy. There is little difference in the appearance of the basal and cauline leaves, although the latter tend to have shorter petioles. The foliage contains a yellow sap. The upper stem terminates in a single flower or a floppy umbel of 2-4 flowers. Each flower is 1-2" across, consisting of 4 bright yellow petals, 2 deciduous sepals, numerous stamens with yellow anthers, and a single pistil with a knobby stigma. The blooming period occurs from mid- to late spring and lasts about 2-3 weeks. After the petals fall off, the pistil matures into an ovoid seed capsule about 1" long. This seed capsule is densely hairy and divides into 4 segments. Numerous seeds are released after the seed capsule splits apart. The root system produces rhizomes, which enables this plant to form vegetative colonies.
Cultivation: The Celandine Poppy should be grown in dappled sunlight underneath a tree, or along the foundation of a building in partial shade. It adapts best to rich loamy soil and moist to mesic conditions. Vegetative growth occurs during the spring before the trees fully leaf out.
Range & Habitat: The Celandine Poppy is an uncommon plant that occurs primarily in southern Illinois; it has also been observed in Vermillion and Cook counties further to the north. Habitats include mesic deciduous woodlands, including the bottom of ravines and the base of bluffs. This species is found in high quality woodlands; it is one of the woodland wildflowers that is threatened by the invasion of Alliaria petiolata (Garlic Mustard).
Faunal Associations: Little is known about floral-fauna relations for this species. The flowers are probably pollinated by bees and possibly other insects. The seeds are distributed by ants, which are attracted to their fleshy appendages (elaisomes). The foliage is toxic and avoided by mammalian herbivores.
Photographic Location: A flower garden in Urbana, Illinois.
Comments: This attractive spring-blooming wildflower adapts well to gardens. It resembles another member of the Poppy family, Chelidonium majus (Celandine), but the latter has yellow flowers that are smaller (¾" across or less) and its seed capsules are hairless, linear and erect. Celandine is a somewhat weedy species that was introduced from Europe; it is a biennial that blooms during the summer. Other members of the Poppy family have flowers that are white, pink, orange, or purplish red. Another common name that is often applied to Stylophorum diphyllum is the Wood Poppy.