A corm is a short, vertical, swollen underground plant stem that serves as a storage tuber (similar to a potato) used by some plants to survive winter or other adverse conditions such as summer drought and heat. Corms are sometimes confused with true bulbs; they are often similar in appearance to bulbs externally, and thus erroneously called by that name. However, corms are stems that are internally structured with solid tissues, which distinguishes them from bulbs which are mostly made up of layered fleshy scales that are in fact modified leaves. As a result, when a corm is cut in half, it is solid; but when a true bulb is cut in half, it is made up of layers. Corms are structurally plant stems, with nodes and internodes, and with buds that produce adventitious roots. On the top of the corm, one or a few buds grow into shoots that produce normal leaves and flowers.