Labellar secretory structures and pollinator food-rewards in representatives of Old World Bulbophyllum Thouars

Detailed studies of the floral anatomy, morphology, ultrastructure, and the occurrence of floral food-rewards in Bulbophyllum are rare. Here, we investigate the structure of the labellum and secretion of labellar food-rewards for ten Asian species of the genus, representing six sections. Labellar tissue of each of these species was examined using LM, SEM, and TEM, and compared with our previous results for representatives of sect. Racemosae and...