Self-incompatibility and myophily in Octomeria (Orchidaceae, Pleurothallidinae) species

Pleurothallidinae (ca. 4,000 spp.) is the largest myophilous group in Orchidaceae. Recently three self-compatible bird-pollinated genera were included at the base of the group, while Octomeria (plus Brachionidium) is the sister group to the remaining subtribe in the former circumscription. Studies of reproductive biology of three Octomeria species were carried out to determine the occurrence of myophily and self-incompatibility in the genus, to help trace the evolution of these characteristics in the subtribe. The three species showed a strong self-incompatibility and are intercompatible. Octomeria crassifolia and O. grandiflora are pollinated by Sciaridae (Diptera) species, presenting high specificity. These results indicate that both self-incompatibility and myophily are basal characteristics in the former delimitation of the Pleurothallidinae and possibly have been kept in the derived lineages, representing biological synapomorphies of the group.