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.