Tuber: A Swollen Underground Stem

A tuber, like a corm, is a swollen underground stem base. But it has no basal plate; roots grow from both base and sides. Multiple growth points are scattered over its upper surface.

An individual tuber can last many years. Some (cyclamen, for example) continually enlarge but never produce offsets. Others, like caladium, form protuberances that can be removed and planted separately.