Anatomy and Chemical Constituency of Trema Micrantha Fruit: Relationship with Dispersal Syndrome and Urban Afforestation

Abstract

Purpose: This study aimed to analyze the anatomy and histochemistry of Trema micrantha fruit to correlate the data with its wide distribution in urban areas.   Theoretical framework: T. micrantha is a native tree species belonging to the Cannabaceae family and grows widely in urban areas, riparian forests, and environmental recovery areas in Brazil. The fruit is of the drupe type and is mainly consumed by avifauna, however, reports on its anatomy and chemical composition are lacking, and the relationship between fruit structure and dispersion syndromes has not been studied.   Method:  The mature fruits were fixed, dehydrated, embedded, polymerized in methacrylate, and sectioned using a rotating microtome. The slides were mounted, stained, and analyzed under a light microscope. Surface analysis was performed using scanning electron microscopy (SEM).   Results and conclusion: The pericarp consisted of an exocarp, a mesocarp, and an endocarp. The exocarp is uniseriate and contained papillae, stomata, and a cuticle. The mesocarp is parenchymatic and subdivided into three regions: external, middle, and internal. The endocarp is uniseriate and contains sclerified cells. Histochemical tests revealed the presence of lipids, proteins, starch grains, phenolic compounds, and alkaloids in the mesocarp.   Research implications: The presence of lipids, proteins, and starch increases the nutritional value of the fruit, indicating its dispersion by animals, mainly birds, and the dispersion of diaspores in urban areas.   Originality/value: T. micrantha contributes to the food chain of local fauna, and their population will benefit from by increasing afforestation.