A bud is a swelling on a plant stem, consisting of numerous overlapping, immature (i.e., not-yet developed), primordial leaves or floral structures (such as petals). The growth of plant buds occurs through the action of a region of rapidly dividing and differentiating tissue, known as an apical meristem.

A plant bud is a complex, compound structure, whose detailed anatomy is revealed by careful dissection and examination using a microscope. The smallest, least developed, leaf or floral primordia occur in the center of a bud, while the older, larger, more developed ones occur on the outside and curve up and over the younger ones, enveloping them in a sheath-like manner. In the center, beneath the youngest primordia, is the meristematic tissue. The dormant buds of many woody plants are protected by several tough, overlapping structures known as bud scales. When used in reference to...