Secretion and use of nectar across floral longevity of the protandrous Tropaeolum pentaphyllum Lam. (Tropaeolaceae)

The herbaceous vine Tropaeolum pentaphyllum Lam. is a geophyte. The species presents potential use as an ornamental, food and medicinal plant. In this study, we aim to understand the reproductive biology of T. pentaphyllum in Brazilian Mixed Ombrophilous Forest, Southern Brazil. Floral structures, duration of the staminate and pistillate phases, interval between phases, overlapping of phases, breeding system were studied. Nectar volume and sugar concentration were evaluated throughout floral longevity. The floral visitor’s behaviour was observed for four years, 6 am to 8 pm, totalling 100 hours of observation each year. Tropaeolum pentaphyllum is protandrous. The mean floral longevity was of 13.6 days. The duration of the staminate ( x = 6.7 days) and pistillate ( x = 6.1 days) phases did not differ. However, all flowers produced nectar in the staminate phase while just 23.3