This herbal is particularly hazardous because its appearance gives undeserved credibility. The colored illustrations are extremely well done and very numerous. Typically, they picture the various parts used of the medicinal herbs, fresh and dried, together with some of the dosage forms prepared from them. The book's format is also attractive. This initial visual feast is likely to lure some readers into believing that the text is equally useful. Unfortunately, such is not the case. Much of the information presented as authoritative is not; errors of commission and omission abound; and many of the assertions are based on hope or belief rather than on scientific or clinically proven facts. And no references are provided that could help careful readers to determine which is which. Thus, English herbalist Penelope Ody frustrates the reader's search for herbal truth much as her namesake, the wife of Odysseus, frustrated her many suitors.
The book is well organized. A short history of herbal use in various cultures is followed by illustrated monographs of some 85 representative plant drugs and a section on the preparation of various dosage forms. Numerous tables enable readers to select herbs for self-treatment of various illnesses, although they are cautioned against such action in the customary small print on the copyright page. The volume concludes with some miscellaneous considerations and an index; it is well printed and well bound in Italy.
A few examples will serve to illustrate the text's unreliability. In May, 1979, the Herb Trade Association urged its members not to sell pokeroot as a food or beverage because of its toxic character. Ody not only monographs the herb but recommends its use for tonsillitis, with the qualifying statement that the fresh, not the dried, root is toxic. She apparently is unaware of a case in Baltimore in 1938 when more than 25 people on six floors of a building were poisoned when dried pokeroot was milled in the structure. Comfrey root is recommended for external use with no mention of the need to restrict application to intact skin. In fact, a poultice is suggested for bleeding hemorrhoids. The occurrence of toxic pyrrolizidine alkaloids (PAs) in the borage plant is not mentioned. In the coltsfoot monograph, it is claimed that PAs may no longer be present in a decoction of the plant-which is untrue.
Moving on from the serious to the ridiculous, placing a pounded cabbage leaf in bra cups for mastitis or engorged breasts is counseled, apparently with a straight face. Hops is said to contain a high proportion of estrogen, a statement that will raise the eyebrows of some pharmaceutical manufacturers who have thought it necessary all these years to process large quantities of pregnant mare's urine for such compounds. It is recommended that fresh, not dried, hops be used for insomnia; yet scientists have shown that 2-methyl-3-butane-2-ol, a sedative principle, increases in concentration in the herb for at least two years after drying.
Botanically oriented readers will be disturbed by the absence of author citations from scientific plant names. The practice of referring to rhizomes or rhizomes and roots (e.g., ginger, rhubarb, valerian) simply as "roots" and the lack of a clear differentiation of aloe gel from the parenchyma cells and aloe latex or juice from the pericyclic tubules are also disturbing. The designation of the plants yielding medicinal rhubarb only as Rheum palrmatum enormously simplifies the numerous species and hybrids of this taxonomically difficult genus.
In summary, aside from the excellent illustrations, there appears to be no justification for publishing this book. Its existence will simply provide more ammunition for the critics of phytomedicines who are looking for evidence that herbalism is unscientific and therefore that herbs are unworthy of consideration. In fact, some uses of herbs are disreputable, but others are not. Publishers who market attractively packaged but scientifically unsound herbals do more harm than they will ever know.
Dr. Tyler, who died in 2001, was the Lilly distinguished professor of pharmacognosy (the science of medicines from natural sources) at Purdue University. A world-renowned authority, he wrote The Honest Herbal, an evaluation of popular herbs, and was senior author of the textbook Pharmacognosy.