Cephalanthus occidentalis. A. Flowering branch. B–D. Variation in leaf form. E. Pocket with domatia as tuft of hairs. F. Partial inflorescence, in bud stage. G. Perfect flower. H. Unfolded corolla. I. Dorsal view of schizocarp. J. Ventral view of schizocarp. K. Longitudinal section through fruit and seed. L. Ventral view of mericarp with opening in apical region (slight manual pressure was exerted to provoke the opening). M. Subventral view of seed with aril. N. Dorsal view of seed with aril. O. Lateral view of seed with aril. Drawn by Laura Simón.