Symplocarpus is a genus in the Araceae family with species native to North America and Asia. Growing from rhizomes, these plants are referred to as skunk cabbage since they smell unpleasant if they are crushed. Another genus with plants known as skunk cabbages is Lysichiton. Plants that Kew lists as accepted are listed below. Only Symplocarpus foetidus, Symplocarpus nipponicus and Symplocarpus renifolius seem to be grown and they are the only three species listed in The Genera of Araceae.
Symplocarpus egorovii is native to Russia.
Symplocarpus foetidus is native to northeastern North America. This species is one of the first to bloom in the spring sometimes barely showing through the leaves or snow. It grows in damp places, often alongside (but not in) streams, mainly in the open, though sometimes under trees. The flowers are pollinated by flies and produce heat which would be a benefit to the flies early in the season when it is cold. The color of the spathe, the outer hood, varies from plant to plant. It can be red, purple, yellowish, greenish, or reddish brown with spots. Skunk cabbage is also an important food for black bears when they first emerge from hibernation. The leaves emerge after the flowers. While oohing over the range of flower (spathe) color, the lovely size and boldness of the foliage are both more obvious than the flowers and much longer lasting. This aroid does have very large round cabbage-like foliage that can stay in very good shape for a long growth period. The flowers are fairly small and fleeting in comparison. Seeing a patch in full growth is very impressive; like a nice architectural Hosta it has 'presence'. The spathe in the first picture, reddish-purple and green streaks, is fairly typical in our area of Pennsylvania. The second picture, below, shows a clump with striking dark purple spathes growing on a damp part of the rock garden at the Royal Botanic Gardens at Kew, when I was a student there in 1975. Photographs by Graham Rice.
Symplocarpus nabekuraensis listed by Kew as native to Japan.
Symplocarpus nipponicus is native to Japan, northeast China, and Korea.
Symplocarpus renifolius is from Asia (Korea, Manchuria, Russia, Japan)