Upas

Upas (Malay, 'poison') is the name given to various vegetable poisons in the Indian Archipelago, including some kinds of Strychnos. But that best known under this name is the arrow-poison prepared from the gum that exudes from incisions in the stem of the Antjar or Anchar tree (Antiaris toxicaria), a large tree belonging to the Artocarpaceæ. The portentous tales current in Europe, especially towards the end of the 16th century, and set forth in Erasmus Darwin's Loves of the Plants, are mostly baseless inventions—as for example that the atmosphere for miles round a upas tree was deadly to all animal life, and that no other vegetation could flourish near one. It is true that when a tree is felled or its bark much bruised an effluvium issues acrid enough to cause cutaneous eruptions. And it has been suggested as an explanation of the fantastic stories that upas trees grow in a Javanese valley where carbonic acid, in quantities dangerous to animal life, issues from the volcanic soil, as in the Grotto del Cane. But the tree has no such powers.