Two new erythrinan alkaloids, 10,11-dioxoerythraline (1) and 8-oxoerythraline epoxide (5) have been isolated from flowers of Erythrina x bidwillii. Their structures were elucidated by spectroscopic analyses and chemical evidence. 8-Oxoerythraline epoxide is the first erythrinan alkaloid possessing an epoxy ring.