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

• Published in: Flora. Morphologie, Geobotanik, Oekophysiologie Vol. 286; p. 151969
• Main Authors: Sbais, Patricia Gonçalves, Mazine, Fiorella F., Thadeo, Marcela, Mourão, Káthia Socorro Mathias
• Format: Journal Article
• Language: English
• Published: Elsevier GmbH 01.01.2022
• Subjects: Anatomy; cell division; Development; endocarp; Eugenia; exocarp; flora; herbaria; light microscopes; meristems; mesocarp; ontogeny; phylogeny; Pyrenarium-like; trichomes; Development; Eugenia; Anatomy; Pyrenarium-like
• ISSN: 0367-2530; 1618-0585
• DOI: 10.1016/j.flora.2021.151969

•The pericarp anatomy of Eugeniinae species revealed Myrcianthes pungens (which is in the genus sister to Eugenia) has a drupe-like fruit.•In species of Eugeniinae, the dorsal and ventral meristems in the ovary wall give rise to a mesocarp with three distinct regions.•This work supports the importance of ontogenic studies to appropriately delimit pericarp layers and may help reveal patterns in the pericarp structure that can contribute to estimating phylogenetic relationships. 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.