Do I need a sexual partner, or is it better to be my own date? The evolution of sexually dimorphic plants

Enantiostyly, a reproductive system characterized by heteromorphic flowers with either left or right style deflection, compels reciprocal pollen transfer between floral types. The potential outcrossing advantage of enantiostyly, however, is blurred when both floral types are produced in the same individual.

Accordingly, Mora-Carrera et al. experimentally explored the conditions favouring the stability of monomorphic enantiostyly (ME) versus invasion by a dimorphic form (DE). Under pollen limitation and lack of consorts’ conditions, ME had higher fitness and equivalent outcrossing rates than DE. Thus, in Solanum rostratum (Solanaceae) ME functions as a reproductive assurance mechanism precludes invasion by a dimorphic form.