The ontogeny of the pericarp in the subtribe Eugeniinae O. Berg (Myrteae Myrtaceae) reveals a drupe-like fruit in Myrcianthes pungens (O. Berg) D. Legrand

The genus Eugenia is of great ecological importance and due to being very diverse has been the subject of a comprehensive phylogenetic and taxonomic review to create an accurate classification. This study sought to describe the pericarp ontogeny of species in the subtribe Eugeniinae to reveal anatomical features that can be used to characterize morphologically similar sections. Buds, flowers, and fruits were collected at different development stages from herbarium specimens and plants in the field. Herbarium material underwent a reversal procedure, and fresh material was submitted to conventional anatomical analysis techniques and evaluated under an optical light microscope. By analyzing the species, we verified some promising characteristics, such as the following: a drupe-like fruit in Myrcianthes pungens (which is in the genus sister to Eugenia) that is a novelty for this species; trichomes in the inner epidermis of the ovary in species in Eugenia sect. Hexachlamys and E. sect. Pilothecium; and the absence of intercellular spaces in the most internal layers of the mesocarp in a species of E. section Speciosae. Representatives from the subtribe showed predominant cell division in the layers subjacent to the exocarp (dorsal meristem) and endocarp (ventral meristem) and the outer, middle and inner mesocarp.

Automated summary

This study investigated the pericarp ontogeny of species in the subtribe Eugeniinae, revealing promising characteristics such as unique fruit structures in certain species and the presence of trichomes in specific sections. Anatomical features were analyzed through conventional techniques, highlighting predominant cell division patterns in different layers of the fruit.