What looks like a bulb, and acts like a bulb, but isn't? Lots of things! Technically, many plants we think of as growing from bulbs, actually grow from other types of modified stems, that behave very similarly to bulbs. For example, Crocus, Gladiolus, and Crocosmia grow from corms, Callas and Cyclamen grow from tubers, Dahlias grow from tuberous roots, and Bearded Iris and Cannas grow from rhizomes.