Toxins, tonics and trips

Only a century ago, medicine was the province of botanists not doctors. Plants provided cure-alls, kill-alls and wonder drugs for our Victorian ancestors. Dangerous Garden explores the intersection between plants and people that has been both good and horribly bad.

The stories of how people discovered and used plants for medicine are as diverse and interesting as the plants themselves. This slender book tells some of those stories while touching on botany, history and economics, highlighting the plants used by people to cure, kill and communicate with the supernatural - drugs, poisons and hallucinogens. It is illustrated with botanical prints, old plates from historical works and a few photographs of live plants; my favourite illustration is the 1519 map of Arabia and India from Reinel's Miller Atlas , replete with peculiar humped elephants, palm trees, intricate forts and spear-bearing natives. It reminds us that the world known to Europeans of the 16th century was a great unknown, full of surprises and novelties. We tend to think of today's world as known, controlled and basically benign, but the tales in this book remind us this is not so: a number of plant species have surprising properties, some of which are dangerous in the extreme.

Unfortunately, David Stuart misses an opportunity to delve more deeply into the science and history of plants and people. His book is full of half-truths and old wives' tales, repeated as if they are fact - which is disappointing because the truth is often more interesting than the tales.

In part, this is because he tries to cover so much in a short space, but I cannot help feeling that more careful research in the primary literature might have resulted in a more interesting volume.

The bibliography is especially disappointing for anyone interested in reading further about the botany and history of the plants discussed. For example, splendid recent books on coca ( Cocaine by Dominic Streatfeild) and the search for a cure for malaria ( The Fever Trail by Mark Honigsbaum) are not mentioned. Also, the botanical names are irritatingly inconsistent. Why are some plants identified by the family to which they belong while others are not?

In many places, only part of the story gets told. It is surely biased to blame the New World for the introduction of syphilis to the Old World without mentioning the introduction of smallpox or gonorrhoea to the New World from the Old. The author's coinage of "Janus plants", to mean plants that are two-faced because they can cure or kill, is novel but misleading.

It is not the plants themselves that produce this effect, but our own use of them - any more than cars are responsible for being very useful for getting from one place to another but harmful for the environment and sometimes lethal weapons. Furthermore, some of the plants are woven into several chapters, which makes it difficult to connect the story of their relationships to particular human conditions.

Dangerous Garden offers a fascinating skim through a great many plants and how they have helped and harmed humans through history. But it is only a beginning, with too little depth and far too much inaccuracy and incompleteness. Read it as an inspiration for exploration, not as an authoritative guide.

Sandra Knapp is a plant taxonomist at the Natural History Museum.