| the seed of any of certain Mexican plants of the genera Sebastiania and Sapium, of the spurge family: the movements of a moth larva inside the seed cause it to move about or jump. |
Mexican jumping bean
the seed of certain Mexican shrubs, especially those of the genus Sebastiania, of the spurge family (Euphorbiaceae), that contain larvae of a small olethreutid moth (Laspeyresia salitans). The movements of the larvae feeding on the pulp within the seed, which are intensified by warmth, give the seed the familiar jumping movement
Learn more about Mexican jumping bean with a free trial on Britannica.com.
