The flowers are yellow-green with an unpleasant odor, bell-shaped, 3/4 to 1 inch long, with 4 petals and 7 long stamens; in upright clusters to 6 inches;  in spring.  The fruit is a thick, leathery, prickly and almost round pod about 1 inch in diameter, borne on a stout stalk;  and usually containing a solitary, large, smooth, lustrous brown nut;  maturing in summer or fall.