This book is designed as an introductory text in botany. It assumes little knowledge of the sciences on the part of the student. It includes sufficient information for some shorter introductory botany courses open to both majors and nonmajors, but it is arranged so that certain sections-for example, "Soils," "Molecular Genetics," "Division Psilophyta"-can be omitted without disrupting the overall continuity of the course.

Botany instructors vary greatly in their opinions concerning the depth of coverage needed for the topics of photosynthesis and respiration in a text of this type. Some feel that nonmajors, in particular, should have a brief introduction only, while others consider a more detailed discussion essential. In this text, photosynthesis and respiration are discussed at three levels. Some may find one or two levels sufficient, and others may wish their students to become familiar with the processes at all three levels.

Many texts for majors and non-majors, while including eye-catching chapter titles and headings, give relatively minor coverage of the current interests of a significant number of students. This text emphasizes current interests without giving short shrift to botanical principles. Present interests of students include topics such as global warming, ozone layer depletion, acid rain (acid deposition), organic gardening, Native American and pioneer uses of plants, pollution and recycling, house plants, backyard vegetable gardens, natural dye plants, poisonous and hallucinogenic plants, and the nutritional values of edible plants. The rather perfunctory coverage or absence of such topics in many botany texts has occurred partly because many botanists have tended in the past to believe that some of the topics not covered in their departmental economic botany courses are more appropriately addressed in anthropology and horticulture courses. I have found, however, that both majors and non-majors in botany, who initially may be disinterested in the subject matter of a required course, often become engrossed if the mateial is repeatedly related to such topics. Accordingly, a considerable amount of ethnobotanical and ecological material has been included with tradtional botany throughout the book - without, however, resorting to excessive use of technical terms.