Wild Flowers of Pittsburgh

Menispermaceae

Moonseed (Menispermum canadense)

A vine that looks a bit like a cucumber and a bit like a grape. The little clusters of white flowers hide among the leaves; much later, clusters of poisonous grape-like berries, easily mistaken for wild grapes, decorate the plant to lure the unwary. This vine was blooming in early June in Frick Park.

Gray describes the genus and the species, which is the only member of the family Menispermaceae in our area:

MENISPÉRMUM [Tourn.] L. MOONSEED. Sepals 4-8. Petals 6-8, short. Stamens 12-24 in the sterile flowers, as long as the sepals; anthers 4-celled. Pistils 2-4 in the fertile flowers, raised on a short common receptacle; stigma broad and flat. Drupe globular, the mark of the stigma near the base, the ovary in its growth after flowering being strongly incurved so that the (wrinkled and grooved) laterally flattened stone takes the form of a large crescent or ring. The slender embryo therefore is horseshoe-shaped; cotyledons filiform. — Flowers white, in small and loose axillary panicles. (Name from mene, moon, and sperma, seed.)

M. canadénse L. Leaves peltate near the edge, 8-7-angled or -lobed. — Banks of streams, w. Que. and w. N. E., westw. and southw. June, July. — Drupes black with a bloom, ripe in September, looking like frost grapes.