Flower structure of Serjania fuscifolia (Sapindaceae) and its relationship with visiting insect

Abstract

Serjania fuscifolia is a species that occurs often in edges of forest fragments, it flowers in the autumn-winter period and is visited by insects. This species constitutes an interesting model of floral biology, especially for its potential to provide food resources to the entomofauna. Its floral structure was investigated, and its relationship with visiting insects was also verified. Five specimens of this species were analyzed in a seasonal semideciduous forest fragment surrounded by agricultural fields in the years 2019 and 2020. Flowers were embedded in historesin and sectioned in a microtome; collections and observations of insects followed a floral biology protocol. Four individuals showed monoecy, with temporal variations in floral types, and only one individual was male unisexual. Both types of flowers showed non-glandular and glandular trichomes, lipid-secreting cells and nectar in abundance. Pollen grains were exposed only on male flowers, while indehiscent anthers on female flowers showed pollen with 35% viability. Flowers consist of perianth with homogeneous mesophyll, anther wall with five cell-layers, style with a trilobed strand of transmitting tissue, and ovary wall with adaxial meristem. The plant was visited by 50 species of insects, with emphasis on Hymenoptera (21 sp.), Lepidoptera (15 sp.) and Diptera (10 sp.)