A much-maligned species that helped curb the plague
Poison made from the treenroots and bark killedn14th-century rats.

When bubonic plague, transmitted by rat-riding fleas, swept across Asia and Europe in the mid-14th century, physicians could do little but comfort the sick and dying. Before strychnine poison helped curb the epidemic by killing the rats, roughly half of Europe's population perished.

The strychnine tree (Strychnos nux vomica), native to Southeast Asia and Australia, provides benefits other than varmint control. The people of Southeast Asia used limbs and boards cut from this tree to build their huts and to fence animals. Primitive hunters made arrow poison for hunting from the bark, roots, and disc-like seeds in the tree's fleshy orange-red berries.

In the 1800s, physicians added small amounts of strychnine to tonics as a stimulant, even though it's so bitter it can be tasted in concentrations of one part per 400,000. This powerful drug may have gotten its start killing game, but today doctors prescribe controlled doses to increase muscular activity and as a antidote for alcohol and drug poisoning.

Illustration: Jim Stevenson