This encyclopedia which aims to be the most modern and comprehensive treatment available of anatomy, embryology, phytochemistry and evolution of vascular plants, with practical keys for classification.
From the publisher's announcement:
This encyclopedia offers access to the diversity of ferns and seed plants, the most important groups of green land plants. Available information of general and systematic relevance is synthesized at the level of families. Evidence from virtually all disciplines important to modern taxonomy makes the work a most valuable source of reference not only for taxonomists, but for all who are interested in the various aspects of plant diversity. A revised classification includes a complete inventory of genera along with their diagnostic features, keys for their identification, and references to the literature.