genus of tropical shrubs or trees of the spurge family (Euphorbiaceae), comprising 15 species; 12 are native to the Americas, 3 to the Old World. O. triandra, the Jamaican cobnut, or pop nut, is native to the West Indies and cultivated in Europe. It grows to about 3.5 metres (11.5 feet) and bears yellow nuts 3.75 centimetres (1.5 inches) thick, which are edible if the poisonous embryo is removed. Juice from the fruit blackens and is used in making ink and glue. O. diandra, native to Colombia, bears edible oily seeds that are also used as hog feed. Large hunter's nuts from O. megacarpa are a stimulating, nutritious food popular in the West Indies.