This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
An erect perennial herb, with palmately-lobed leaves, and small white dioecious flowers in ample terminal corymbose panicles. Involucels none. Calyx 5-toothed. Petals entire. Staminate flowers with 15-20 anthers borne at the summit of the stamen-column. Pistillate flowers with 8-10 styles, stigmatic along their inner surface, the stamen-column present but destitute of anthers. Cavities of the ovary as many as the styles, I-ovuled. Carpels 8-10, separating at maturity from the axis, beakless, but minutely tipped, imperfectly 2-valved. Seed ascending. [Greek, a dell.]
A monotypic genus of the east-central United States.
Napaea dioica L. Sp. Pl. 686. 1753.
Simple, or branching above, 4°-9° high, pubescent or glabrate. Basal and lower leaves 6'-12' broad, long-petioled, orbicular in outline, 7-11-parted nearly to the base, the divisions acute, dentate and lobed; upper leaves smaller, short-petioled, 5-9-lobed, the lobes incisely cut, acute or acuminate; staminate flowers 6"-9" broad, the pistillate somewhat smaller; petals obovate, 2-3 times the length of the calyx; carpels strongly 1-nerved, slightly rugose-reticulate.