The genus Consolea Lem., subfamily Opuntioideae, comprises nine species endemic to the Caribbean region and distributed from the Florida Keys across the Bahamas and the Greater Antilles to Guadeloupe. Within this group, C. spinosissima (Mill.) Lem. is a species endemic to Jamaica, and C. rubescens (SD.) Lem. occurs in Hispaniola, Puerto Rico and Lesser Antilles. According to taxonomic descriptions these species have perfect flowers, but our recent observations reveal sexual dimorphism. Within populations of both species are plants with numerous fruits and whose flowers appear to be perfect, but have anthers that do not produce pollen grains. Other individuals do not produce fruits, and the stigma lobes remain closed. Embryological studies have shown that flowers of the two sexual morphs begin as perfect. Later, during sex differentiation, microsporogenesis ceases in flowers of the female morph and flowers of the male morph present aborted megaspore tetrads. These data indicate that C. spinossisima and C. rubescens are cryptically dioecious, and were derived from a hermaphroditic ancestor. In general, this study will provide additional characters useful for the taxonomy of Consolea.