Subject and aims of the book

This book deals with a fascinating subject in plant morphogenesis called phyllotaxis. In the various areas of botany, phyllotaxis is often considered to be the most striking phenomenon and the toughest subject, raising the most difficult questions. Phyllotaxis studies the symmetrical (asymmetrical) constructions determined by organs and parts of organs of plants, their origins, and their functions in the environment. These constructions are the phyllotactic patterns, and their building blocks, in their young stage, are called the primordial. The primordia differ in number, size, position, rate of formation, and shape, thus giving considerable diversity to phyllotactic patterns. Yet the phenomenon of phyllotaxis is simple, insofar as all the phyllotactic systems showing spirality belong to Fibonacci-type sequences of integers, characterized by the rule that every term in it is the sum of the preceding two terms, as in the Fibonacci sequence <1,1,2,3,5,8,13, …>.

In a well-known chapter on phyllotaxis, Coxeter (1969) calls the appearance of the Fibonacci sequence in botany a “fascinatingly prevalent tendency,” called by Cook (1914) “the Law of Wiesner. ” The prevalence of the Fibonacci sequence in phyllotactic patterns is often referred to as “the mystery of phyllotaxis, ” and “the bugbear of botanists.” These Fibonacci patterns are one of the most puzzling products of the activity of apical meristems, buds, and shoots. Their study has brought about new ideas and considerable progress in our knowledge of the organization of vegetative shoots and reproductive structures in plants.