Bulbs consist of a growing point surrounded by layers of fleshy leaf bases. These are attached to a compact stem call the basal plate.
Bulbs are classifies as tunicate or non-tunicate.
The onion, hyacinth, squill, amaryllis, snowdrop, tulip and daffodil are examples of tunicate or nonscaly bulbs. These have the fleshy leaf bases arranged in concentric layers around the growing point. The fleshy leaf bases composing these bulbs overlap resulting in a scaly appearance. Scaly bulbs lack the protective tunic and consequently are more easily damaged and suffer from dessication more readily than tunicate bulbs. It may be several years before the bulb is of sufficient size to produce a flower.