A new isoflavan, erythbidin A, was isolated from the wood of Erythrina x bidwillii, together with three known isoflavans, phaseollinisoflavan, 2'-methoxyphaseollinisoflavan, and 2'-O-methylphaseollidinisoflavan and another pterocarpan, sandwicensin. Erythbidin A has a dimethylpyrene substitution at the 2',3'-position.