below-ground, usually short lived storage and regenerative organ of shoot origin; offspring tubers are attached to a parent tuber or produced at the end of a hypogeogenous rhizome; the parent plant dies back in autumn, except for the stem tuber(s) which bear one dominant bud, each utilised for spring regrowth; in summer old tubers decay and new ones are formed; in addition some plants produce smaller tubers and/or tubercules; plants growing from them resemble seedlings in morphology and size
