Though no relation to rhubarb and definitely prehistoric looking, Giant Rhubarb, also known as Dinosaur Plant, dominates shade gardens and boggy spots with its massive rhubarb-shaped leaves that are toothed and puckered, and its thick prickly stems. Its botanical epithet "manicata" means "with long sleeves," for obvious reasons. Massive in height and breadth at the peak of summer, gunnera all but disappears in the winter. Native to southern Brazil, gunnera prefers shade or filtered sun and doesn't like its roots to dry out.