The Probert Encyclopaedia of Nature

UPAS

The upas (Antiaris toxicaria) is a tree of the family Urticaceae, allied to the fig, hop and nettle, found in Java and exuding a milky white juice called antiarin which is allied to strychnia. The milky juice that exudes from the incised bark is extremely virulent and is used for poisoning arrows. On the basis of this single fact a mass of legend was built up, as, for example, the story that nothing could live within a considerable radius ten or twelve miles of the tree, so virulent was its effluvia.
Research Upas