The First Book of Plants by Alice Dickinson is a wonderful science book that targets upper elementary/middle school readers. It is very thorough in its presentation of plants as organisms, discussing the different types of plants (annuals, biennials, and perennials and various examples of each, bacteria and fungi), The book discusses the many ways that plants reproduce, a discussion of seeds and fruit, and the parts and components of plants, from the cellular level to their structure. Beautiful illustrations by Paul Wenck are contained throughout the text. Some basic experiments are included. An index is provided. This book was originally intended for upper elementary grades but because of its broad coverage of the material, would be valuable reading for upper grade levels as well.