Bulb
Bulb, mass of overlapping, usually fleshy leaves on a short stem, enclosing, protecting, and serving as a source of food for at least one bud that may develop into a new plant. The bulb, usually developed underground, has roots growing down from the stem. The truncated bulb, as in the onion, has tightly overlapping leaves; the scaly bulb, as in garlic, is looser. In common usage the term bulb also refers to bulblike stems, such as the corm of the crocus or the tuber of the dahlia, and even to rhizomes, masses of roots, and some underground stems. See also Rhizome; Tuber .