This is a term loosely used to include corms, tubers, tuberous roots, and rhizomes as well as true bulbs. This section of the chapter will refer to all of the above as bulbs. However, a true bulb is a complete or nearly complete miniature of a plant encased in fleshy modified leaves called scales which contain reserves of food.
Corms are the base of a stem that becomes swollen and solid with nutrients.
It has no fleshy scales. The tuber, which is an underground stem that stores food, differs from the true bulb or corm in that it has no covering of dry leaves and no basal plant from which the roots grow. Usually short, fat and rounded, it has a knobby surface with growth buds, or eyes, from which the shoots of the new plant emerge. Rhizomes, which are sometimes called rootstocks, are thickened stems that grow horizontally, weaving their way along or below the surface of the soil and at intervals sending stems above ground. Spring bulbs provide early color before most annuals and perennials.