Secretory cavities and pellucid dots in leaflets of Lonchocarpus (Leguminosae, Papilionoideae, Millettieae)

The occurrence of leaflet secretory cavities in 23 Brazilian species of Lonchocarpus was surveyed anatomically and compared with data from external morphology (presence of pellucid dots) to evaluate their taxonomic significance. This study revealed three cases: presence of secretory cavities associated with pellucid dots, pellucid dots corresponding to false secretory cavities, and absence of pellucid dots and secretory cavities. These results indicate that in this genus the "glandular pellucid dots" cited in morphological descriptions do not always correspond to secretory cavities, and that their nature must always be confirmed by histological sections. Secretory cavities have systematic significance at subgeneric taxonomic level for the genus Lonchocarpus.