Corm

Corm (Gr. kormos, 'a stump')—sometimes called a solid bulb—the short and bulb-like subterranean stem of many monocotyledonous plants, e.g. crocus, gladiolus, tuberose, and arising through the annual storing of starch to be consumed by the next year's bud and flower. In functions, as in general appearance, the corm resembles the Bulb (q.v.); a vertical section, however, shows that while in each we have indeed a stem and leaves, the thickening is confined in the former case to the stem, in the latter to the leaves. Transitional forms occur, indeed, in most bulbs; the thickened leaves arise from a more or less thickened and shortened—i.e. corm-like—base. While a section of a corm shows the origin of its usually membranous leaves, and many corms produce new subterranean buds in the axils of their leaves, in either case they arise on the upper surface or sides of the parent corm, and there thicken as new corms. When borne on the upper surface, the new corms then gradually approach the surface of the ground as in crocus.