Tubercle

Tubercle, a fleshy enlargement resembling a tuber (q.v.), but without "eyes," as in many terrestrial orchids, the lesser celandine, the bladder-wort, and other plants. It serves as a reservoir of reserve-material. In the orchids, for instance, in which it may be rounded or palmate, it is mainly filled by the leaf-activity of early summer and exhausted by the flowering in the succeeding year, by which time another has begun to form.