The term bulb is commonly used for corms, rhizomes, and tubers. The true bulb can be described as a sphere like structure that has dry, scale type leaves around the structure. The scales are attached at the base of the bulb. Roots arise from this base. Tulips and Lilies are examples of true bulbs.

Corms are very much like bulbs, except that corms have a swollen base where the food is stored. Buds are generally found on the surface of the corm. Crocus and gladiolus are good examples of corms.

Both bulbs and corms contain all the elements needed for growth. The bulb contains the nutrients needed to sustain growth for the first growing season.