Systematic botany is the science of classifying and naming plants. Plant taxonomy lays emphasis on classification as an expression of phylogenetic relationships, and nomenclature provides each species with a name. Some people's interest in systematic botany is satisfied by a knowledge of the local flora and an ability to identify it, an interest that has been widened by automobile travel. This is but a limited aspect of a large subject. Important work in this field is the building of great herbaria with specimens from all over the world classified chiefly by comparative morphology.
It is designed to cover one semester, preferably the second, so that the fundamentals may be established during the colder months, and supplemented by field work with the opening of spring. Systematic botany should be preceded by a course in general botany, without which the student will fail to grasp the fundamental principles of phylogenetic taxonomy and will find that the examples used are mostly unfamiliar and meaningless. It is not intended that this text shall in any way supplant the manuals used for identifying plants. These are already numerous and cover the flora of practically every part of the country, though lacking somewhat in harmony of detail, and this book is to supplement rather than to compete with them.