Description: This native biennial plant is about
1–2½' 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.