Waterleaf family (Hydrophyllaceae)
Description: This native biennial plant is about 12½' tall, branching occasionally. The stems have a tendency to zigzag between leaves and are quite hairy. The alternate leaves are up to 6" long and 6" across. The lower leaves are pinnately cleft into 5 lobes; they are longer than broader, dentate along the margins, and slightly hairy. The earliest of these lower leaves have patches of greyish white or light green toward the middle of the upper surface, providing them with a water-stained appearance. The middle to upper leaves are orbicular and cleft into 5 lobes; they are dentate along the margins, slightly hairy, and have a maple-like shape. The petioles of these leaves are rather long, stout, and hairy. The upper stems terminate in floppy cymes of flowers. These flowers are about ½" across and become more erect while in bloom. Each flower consists of a lavender or pale purplish pink corolla that consists of 5 spreading petals; at the base of this corolla, is a hairy green calyx with 5 narrowly triangular teeth. Between each pair of teeth on the calyx, there is a short appendage that is strongly recurved. Toward the center of the corolla, there are 5 stamens with light to medium brown anthers and a white style that is divided toward its apex. The blooming period occurs from late spring to early summer and lasts about 3 weeks. Each flower is replaced by a 2-chambered capsule containing several seeds. The root system consists of a taproot. This plant spreads by reseeding itself.
Cultivation: The preference is light dappled shade, moist to mesic conditions, and a rich loamy soil containing abundant organic matter. Sometimes this plant succumbs to fusarium wilt and other wilt-causing fungi.
Range & Habitat: Great Waterleaf occurs occasionally in central and northern Illinois; it is less common or absent in the southern and extreme NW areas of the state (see Distribution Map). Habitats include moist to mesic deciduous woodlands, woodland borders, areas adjacent to woodland paths, shaded or partially shaded seeps, and shaded or partially shaded areas along rivers. This woodland wildflower begins to bloom after the leaves of the trees have partially developed.
Faunal Associations: The nectar and pollen of the flowers attract various kinds of bees, including honeybees, bumblebees, Mason bees, Miner bees, Andrenid bees, and Halictid bees (including Green Metallic bees). Various flies also visit the flowers, but they usually feed on the pollen and are non-pollinating. An exception is Rhingia nasica, which has a proboscis that is long to enough to suck the nectar and pollinate the flowers. Except for these flower visitors, surprisingly little appears to be known about floral-fauna relationships for this species.
Photographic Location: A woodland flower garden on the campus of the University of Illinois in Urbana, Illinois.
Comments: Great Waterleaf is one of the more common Hydrophyllum spp. within the state and its flowers are the most attractive. This species has hairy stems and calyxes, and some of its leaves are maple-shaped. A distinctive characteristic consists of the small recurved appendages between the teeth of the calyx, hence the "appendiculatum" in the scientific name. Other Hydrophyllum spp. lack these strongly recurved appendages and they have less showy flowers. The species Hydrophyllum virginiana (Virginia Waterleaf) and Hydrophyllum canadense (Canada Waterleaf) have smooth stems and hairless calyxes, while Hydrophyllum macrophyllum (Large-Leaved Waterleaf) lacks cleft orbicular leaves with a maple-like appearance. The leaves of this latter species are always longer than broad, and they are pinnately divided to an even greater extent than the lower leaves of Great Waterleaf.