About Napaea dioica L.
Napaea dioica L. grows 1.5 to 3 metres (5 to 10 ft) tall, and has leaves that can reach up to 75 centimetres (30 in) in length. These large leaves are alternately arranged; lower leaves are nine to eleven parted, and have short hairs on their undersides. Individual plants produce more than one flowering stem. Its white flowers bloom for 4 to 5 weeks, starting in late June. Each flower has five petals and five sepals, and flowers are arranged in a panicle. Blooms open in the morning and close at sundown. This species is dioecious, meaning male and female reproductive structures grow on separate individual plants. The fruits are rounded; when ripe, they split into many-seeded, indehiscent locules. Napaea dioica L. grows in areas with moist soil, and tolerates conditions from full sun to partial shade. In Minnesota, where the species is classified as endangered, it grows in alluvial meadows of the Mississippi River and its tributaries, alongside other large herbaceous perennials including Heracleum lanatum, Silphium perfoliatum, and Rudbeckia laciniata. This species is distributed from east-central Ohio, across central Indiana and the northern half of Illinois, to southwestern Wisconsin, southeastern Minnesota and northeastern Iowa. It prefers damp growing conditions, and can also be found growing in ditches or on stream banks.
