Isolona zenkeri A flowering branch B flower C fruit. Isolona campanulata D flowering branch; E flower E corolla lobe opened G fruit. Isolona thonneri H flowering branch I flower J fruit A from Le Testu 5117 B from Le Testu 8001 C from Klaine 2675 D–G from Aubréville 6 H, I from Vrydagh 34 J from Lebrun 2032. Drawings by Hélène Lamourdedieu, Publications Scientifiques du Muséum national d’Histoire naturelle, Paris; modified from Le Thomas (1969b, pl. 67, p. 359).