Dioecious Solanum species of hermaphroditic origin is an example of a broad convergence

Abstract

Unlike the taxa in some genera which show a range of variability in floral morphology, species of Solanum deviate very little from the typical hermaphroditic flower. The known deviant taxa fall into two classes: most are andromonoecious (male and hermaphroditic flowers on the same plant), and the remaining few are androdioedous (male flowers on one plant, hermaphroditic flowers on another)¹.I report here evidence for the first instance of a truly dioecious species of Solanum, a significant discovery in the light of the floral uniformity of this large (second only to Senecio) and economically important genus. The most closely related species and species groups comprise only hermaphroditic forms; this dioecious species is among the few non-hermaphroditic forms native to the New World, the area of greatest species diversity of the genus. Furthermore, as shown below, the species is characterised by a functionally, though not morphologically, dioecious condition. Finally, this demonstration that the two floral forms represent different sexes of the same species, rather than (as originally described) different species, impels closer analysis of other species pairs.