On the question of sugary exudates external to the orchid flower, I have always assumed they function to attract ants to the orchid plant and/or flower. The ants, in turn, would then protect the orchid from herbivorous insects. (I believe a similar situation can be found in the peony.) Considering the intimate relationships found between ants and other tropical plants, this would be a natural extension. Although guttation is associated with reducing fluid pressure and does contain water and minerals, I find it difficult to believe that orchids are in a position to "fritter away" excess sugar.
Dave _______________________________________________ the OrchidGuide Digest (OGD) orchids@orchidguide.com http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com