Book excerpt: "Researchers, get busy!" and "caveat emptor" are the messages of this iteration (last, 1993; first, 1982) by herbalists Tyler (pharmacognosy, Purdue U.) and Foster, as they cull herbs' healing virtues from the hype. Alphabetical entries from alfalfa to yucca provide: a brief description, proper nomenclature, plant from which derived, comments on usage, accessible discussion of the chemistry/pharmacology of its active components, evaluation of probable utility, and references. A 16-page summary chart may alone be worth the price. No illustrations, though. Annotation copyrighted by Book News, Inc., Portland, OR