Flora of the Santa Ana River and Environs

Oscar Clarke and his co-authors, Danielle Svehla, Greg Ballmer, and Arlee Montalvo, have produced a unique and compelling guide to the flora of the lower Santa Ana River watershed from the base of the mountains (about 3,000’ elevation) to the coast, and comprising portions of San Bernardino, Los Angeles, and Orange counties. Not only is this book a guide to the individual plants of the area (over 1000 are covered), it is a synthesis of the current state of plant phylogeny (what plants are related to one another, and at what level). The book itself is a bit large for taking into the field, but will provide ample reward for those who stash it in their daypacks.

Clarke states at the outset (page vii), “My approach to the interpretation of plant life forms and the identification of individual species is largely based on comparative anatomy, as it is visually perceived . . . . As a general botanist, I have never been satisfied by only knowing the name of an organism without associating it with its relatives and seeing it within the evolutionary continuum.” It is clear that this book has been organized and produced to directly address these concerns, and in doing so, it is an unequivocal success.

The inside front cover provides a quick reference to the major plant families of the region, using flower characteristics that are illustrated by photos and are keyed to specific pages in the book. The inside back cover lists all the plant families covered in the book, alphabetically, with their corresponding page number. These features will be helpful to all readers and users of the book.

The overall phylogenetic organization of the book will be bewildering to those not familiar or comfortable with the recent explosive reorganization of plant family concepts that have occurred due to molecular-level botanical investigations. But, if readers can get beyond their initial confusion, they will rapidly develop a deeper and much more meaningful way of organizing their minds about these concerns and will become much better field botanists or natural history buffs as a result. Even native plant gardeners will gain a better understanding of the local flora—and of the relationships that exist in the flora state—and worldwide.

The book is well illustrated with numerous color photos and line drawings that all contain a drawing of a US penny for size comparison. All of the images are of high quality and can readily be used to discern the differences between closely related species. However, some plants are not illustrated at all, and there does not seem to be a clear pattern to this anomaly.

Any floristic treatment must address the “dinkophytes,” those tiny plants often of disproportionate interest to botanists but confounding or difficult for the lay public. By providing numerous enlarged color illustrations of these plants to clearly show both their beauty and key differences, the door has been opened wide for everyone to inspect and enjoy these underappreciated species.

A publication this good is a reflection of its authors and publisher—and we are indeed far more than merely fortunate to have this excellent book encompassing the depth of knowledge, experience, and deep appreciation for the plants of Southern California’s Santa Ana River region by such an accomplished group of professionals. I highly recommend that you own and use at least one copy!

Bart O’Brien, horticulturist
Claremont, California