Can Miconia Ruiz & Pavón fruit anatomical characters have taxonomic usefulness in the genus?

Abstract

Miconia Ruiz & Pavón is currently recognized as a single genus belonging to the Miconieae tribe, whose taxonomic position is in urgent need of new multidisciplinary studies, including the anatomical investigation of fruits and seeds. Our study investigated the structural ontogeny of fruits and seeds of six species of Miconia, from the floral phase. Flowers and developing fruits were obtained from specimens collected in a state park in Paraná, Brazil, and from herbarium specimens. The samples were sectioned in a rotation microtome and analyzed in a light microscope. All species bear berry-subtype pomaceous fruits that originate from inferior or semi-inferior ovaries. The pericarp is fleshy parenchymatous with sclereid idioblasts. The seeds come from anatropous ovules, are testal and exhibit variation in the position of the mechanical cell layer within the testa. Taxonomically consistent features were found, such as position of the ovary and carpel number (inferior or semi-inferior/3 or 4 carpels), exocarp indumentum, mesocarp structure (tissue region), pomaceous fruit with hypanthium totally or partially adnate to the ovary wall, type of seed (exotestal, exomesotestal and mesoendotestal) and sclereid composition of the mechanical layer.