Patterns and implications of floral nectar secretion, chemical composition, removal effects and standing crop in Mandevilla pentlandiana (Apocynaceae)

apidae apocynaceae chemical composition colibri composition chimique drug plants fleur floraison flores flowering flowers hummingbirds nectar oiseau mouche plantas medicinales plante medicinale polinizadores pollination pollinators pollinisateur pollinisation saccharose secretion sucrosa sucrose