Consolea Lem., subfamily Opuntioideae, comprises nine species endemic to the Caribbean region. Within this genus, C. corallicola Small. is a species with a single remaining wild population of only 12 individuals on Little Torch Key, FL. Floral morphology indicates that this species is hermaphroditic. The flowers produce viable pollen grains, but rarely set viable seeds. When seeds do initiate they do so by agamospermy. Embryological studies show that although the flowers begin as hermaphrodites, at anthesis the ovules are aborted and papery. During sex differentiation, the megagametophytes are characterized by an excessive presence of starch grains, indicating abortion. The anthers have a normal developmental process, resulting in viable pollen grains. The study suggests that these superficially hermaphroditic flowers are functionally staminate, and that all surviving individuals are males. Therefore, we hypothesize that C. corallicola had a cryptically dioecious system, which we have also found in other Consolea species. The female sexual morph is, apparently, extinct.

Key words: Cactaceae, Caribbean, conservation, Consolea, cryptic dioecy, embryology