Catalpa \Ca*tal"pa\, n. [From the language of the Indians of Carolina, where Catesby discovered this tree in the year 1726.] (Bot.) A genus of American and East Indian trees, of which the best know species are the {Catalpa bignonioides}, a large, ornamental North American tree, with spotted white flowers and long cylindrical pods, and the {C. speciosa}, of the Mississipi valley; -- called also {Indian bean}.