REPRODUCTIVE BIOLOGY OF Antigonon leptopus HOOK. & ARN. (POLYGONACEAE) IN PARANÁ, BRAZIL Nicholas A. Belliveau, Gustavo H. S. Pereira, Douglas Galhardo, Amanda do Carmo

Abstract

The floral morphology and pollination biology of Antigonon leptopus are poorly understood. This plant has hermaphroditic that exhibit protandry, when male fertility precedes female fertility. This study compares the reproductive traits of three populations of A. leptopus in Paraná, Brazil to those described in the literature. The plant’s floral visitors were recorded, and their behaviors compared. Variable floral traits (e.g. perianth diameter, tepal number) were quantified and general descriptions of morphology and protandry were made. The taxonomic identities of floral visitors and the duration and frequency of their visits were recorded. Variable merosity, a morphological novelty, was observed, with 4 or 5 tepals and 7 or 8 stamens per flower. The means of these variables concerning the perianth’s height and diameter were lower than the values described in literature, according the Student’s t-test. Protandry was observed in three phases (chronologically: male, hermaphroditic, female), contrary to the literature’s male and female phases. PERMANOVAs showed that throughout the day, visitor assemblages differed not between flowers in different phases, but between populations. Tukey’s HSD tests demonstrated that certain bees (e.g. Apis mellifera, Scaptotrigona sp.) performs frequent, but short visits, while halictid bees made fewer, but longer visits. Overall, this study presents novel observations of floral morphology and protandry in Antigonon leptopus, which differ from what was previously described. Our results, along with new floral visitor data, may assist the understanding of how this pantropically introduced plant exotic continues to persist outside its natural range.