Important structures in plant development are buds, shoots, roots, leaves, and flowers; plants produce these tissues and structures throughout their life from meristems located at the tips of organs, or between mature tissues. Thus, a living plant always has embryonic tissues. By contrast, an animal embryo will very early produce all of the body parts that it will ever have in its life. When the animal is born, it has all its body parts and from that point will only grow larger and more mature. However, both plants and animals pass through a phylotypic stage that evolved independently and that causes a developmental constraint limiting morphological diversification.
Variation in leaves from the giant ragweed illustrating positional effects. The lobed leaves come from the base of the plant, while the unlobed leaves come from the top of the plant.
Roots forming above ground on a cutting of Odontonema, also known as firespike
In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of a stem. Once formed, a bud may remain for some time in a dormant condition, or it may form a shoot immediately. Buds may be specialized to develop flowers or short shoots or may have the potential for general shoot development. The term bud is also used in zoology, where it refers to an outgrowth from the body which can develop into a new individual.
European beech (Fagus sylvatica) bud
Inflorescence bud scales in Halesia carolina
Terminal, vegetative bud of Ficus carica
Alnus glutinosa bud