Guide to Texas Grasses by Robert B. Shaw (review)

Botanical treatises represent a lifetime of work; Guide to Texas Grasses illustrates this simple statement. Robert Shaw’s latest addition to the descriptive taxonomy of Texas grasses, crafted with a mixture of line drawings and photographs, leads students through the complexities of grass identification. With its general discussion of “why grasses” and proceeding to descriptions of grass morphology and the ecophysiology of Texas that determines what grasses grow where and why, the volume will be an important addition to the bookshelves of amateur botanists, seasoned rangeland professionals, and tenured taxonomists; it contains information pertinent and usable to a wide range of people interested in grasses.

Guide to Texas Grasses is a mix of general and specific information on the ecology, taxonomy, and identification of grasses. Chapter 1 offers a general discussion of why grasses are important to human civilization and includes factual tidbits on the economic value of Texas grasses as well as amusing anecdotes that stimulate the reader’s interest (popcorn is an exploded endosperm). “The Grass Plant,” chapter 2, is a concise yet complete description of grass morphology that any university or college course in grass taxonomy or identification would find useful. Written descriptions are augmented with line drawings illustrating the simple yet tremendously variable morphological structures that define grasses. Information more specific to Texas—its geology, geography, and climatic zones that determine the expression of vegetation across the landscape—is the focus of chapter 3. Although naming in this section is somewhat local in context (Llano Uplift, Trans-Pecos), information is still general enough for a student from the northern Great Plains to learn about ecoregion classification in land use planning. Descriptions of Texas ecoregions, which span the continuum between coastal prairies and marshes to dry mountains, will be useful to a broad range of teachers and students from within and outside the state.

Taxonomy is always an evolving story, and Robert Shaw gives a brief explanation of his views on grass nomenclature in chapter 4. The bulk of the book, almost 1,000 pages, is taken up with detailed keys and species descriptions (chapter 5). The keys are complicated for a Canadian accustomed to the number and representation of grass tribes, genera, and species being a magnitude lower, although they do follow common terminology and convention used in almost all grass taxonomy. The final section’s strength is clearly in its abundance of line drawings and illustrations, which show detailed morphology of each of 668 Texas grass species; line drawings are also used extensively in the key to demonstrate differences at each step in the keying process. Although brief, each species description gives adequate information on distribution, habitat, and ecological and biological value useful to a variety of readers.

The value of a book can be measured by the breadth and diversity of the audience that finds it informative. Robert Shaw has included something for almost everyone in his Guide to Texas Grasses. Ecologists and taxonomists, biologists and agriculturalists, and lumpers and splitters will find material to help and intrigue them in their understanding of grasses. And, as Shaw astutely points out, as go the grasses, so goes human society.