A tall, perennial herb that sometimes develops woody stalks. One of the largest wildflowers in Missouri, about 6 inches across. Flowers resemble hibiscus flowers, with 5 petals and many protruding stamens united around the style, with a spreading head; petals white or rose with a central wine-purple spot. Blooms July–October. Leaves alternate, large, somewhat heart-shaped, rarely lobed, toothed, often with dense, fine hairs.
Similar species: Halberd-leaved rose mallow (H. laevis) has leaves shaped like halberds (an ancient type of lance with 1 long point at the tip and 2 shorter, spreading lobes pointing away at a sharp degree angle at the sides). Its petals are more commonly pink and the stems and leaves lack hairs. The two rose mallows have been known to hybridize.
Height: to 8 feet.
Mostly in eastern, southern, and southeastern Missouri; cultivated statewide.
Habitat and Conservation
Occurs in borders of lakes and ponds, sloughs, swamps, ditches, and wet lowlands. In addition to our two native rose mallows, a nonnative species sometimes escapes cultivation: Rose of Sharon (or shrubby althaea) (H. syriacus) is a woody, many-branched shrub or small tree that grows 3-18 feet high. Aside from landscape plantings, it is usually found along roadsides, railroads, thickets, and woods. Fortunately, it is not very aggressive.
This plant is a good native choice for the wet garden. Many of its relatives in the mallow family are economically important to people. Other mallows include cotton, okra, hollyhocks, hibiscus, and marsh mallow, the original medicinal plant used in making the sweet, fluffy confection.
The seeds are eaten by ducks and quail. Bees visit the flowers. The caterpillars of several butterflies and skippers feed on the leaves. Japanese beetles, a colorful but troublesome introduced pest, eat the leaves, too. Plants that grow in wet areas purify water and help prevent flooding.