Geranium family (Geraniaceae)
Description: This native perennial plant is 1-2½' tall, consisting of a loose cluster of basal leaves and flowering stems that develop directly from the creeping rootstock. On the lower portion of each flowering stem, there is a pair of opposite leaves. Both the basal leaves and the lower opposite leaves of the flowering stems have a similar appearance. They are up to 5" long and across, and palmately cleft with 5 deep lobes. Each of these lobes is wedge-shaped at the base. The leaf margins have a few secondary lobes and coarse teeth. Each leaf has long petioles with coarse white hairs, while its upper surface has fine white hairs. The flowering stems are covered with coarse white hairs and more or less erect. The upper pairs of leaves on the flowering stems are like the lower leaves, except they are smaller in size and usually have only 3 primary lobes.
The stems terminate in a corymb or floppy umbel of 1-5 flowers. Each flower is about 11½" across, consisting of 5 rounded petals, 5 green sepals, 10 stamens with pale yellow anthers, and a single pistil with 5 carpels. The petals are pale purplish pink and have fine lines running across their surface that function as nectar guides. Both the flowering stalk (peduncle) and pedicels have non-glandular hairs. The blooming period occurs during the late spring to early summer and lasts about a month. The pistil of the flower elongates into a beak-like fruit about 11½" long. As it matures, the 5 slender carpels of this fruit curl upward and backward to fling the seeds from the mother plant. Each of these small seeds has a reticulated surface. The root system consists of a dark stout rootstock that produces rhizomes. It is high in tannins. This plant often forms colonies.
Cultivation: The preference is light shade to partial sunlight, moist to slightly dry conditions, and rich loamy soil with abundant organic matter. This plant also tolerates full sunlight. It is one of the easier woodland species to grow.
Range & Habitat: Wild Geranium is a common plant of woodlands that occurs in all counties of Illinois. Habitats include both floodplain and upland woodlands, savannas, meadows in woodlands, semi-shaded seeps, and glades. Sometimes it invades hill prairies from adjacent wooded areas. It is a typical species of mesic deciduous woodlands.
Faunal Associations: The nectar and pollen of the flowers attract bumblebees, Mason bees, Halictid bees, Andrenid bees, Nomadine Cuckoo bees, Miner bees, and others. The flowers also attract Syrphid flies, March flies (Empidae), small butterflies, and skippers. The caterpillars of some moth species feed on either the foliage or flower buds, including Lacinipolia lorea (Bridled Arches), Heliothis virescens (Geranium Budworm Moth, Tobacco Budworm Moth), and Hemerocampa leucostigma (White-Marked Tussock Moth). Chipmunks eat the seeds, while deer occasionally eat the foliage.
Photographic Location: A flower garden at Crystal Lake Park in Urbana, Illinois.
Comments: The Wild Geranium is the showiest of the native geraniums with flowers at least 1" across. All of the others are far less showy because they have smaller flowers. There is a European species, Geranium pratense (Meadow Geranium), with equally large flowers, but it has not been observed in the wild in Illinois. This species has a similar appearance to the Wild Geranium, except that the hairs on the flowering stalks and pedicels are sticky glandular, and the leaves are more divided and finely cut. Another European species, Geranium sanguineum (Long-Stalked Geranium), is rarely observed in Illinois. It has flowers with notched petals and the foliage is divided into more narrow lobes.