A MORPHOLOGICAL SURVEY ON THE REMARKABLE FLOWER OF Dillenia indica (DILLENIACEAE) Beatriz Dean Rizzo, Maria Juliana da Silva, Cláudio Gomes da Silva Júnior, Geovana Gentilin Martins, Michelle Rodrigues de Souza, Luiz Antonio de Souza, Odair J. García de Almeida, J. Hugo Cota-Sánchez

Abstract

Within the flower, the stamens are among the structures that have undergone morphological and functional changes. The pantropical family Dilleniaceae includes ca. 400 species distributed in four subfamilies and 11 genera is among the flowering plants with flowers combining primitive and ancestral structures and poricidal anthers. The aim of this study was to illustrate the general structure of flowers and anthers in Dillenia indica. Flower parts are spirally organized including the apocarpous gynoecium composed of 16 to 22 carpels. The androecium has numerous free heterodynamous stamens, spirally organized in several concentric series that can be distinguished in peripherical and central series; the long anthers are poricidal. The ovary is epigynous and polycarpous with many ovules per carpel, axile placentation and anatropous ovules. The sepals persist during development and wrap an indehiscent fruit. All floral whorls are spirally arranged in a Magnoliid-fashion and showed some distinctive characters, such as perianth with persistent sepals that remain attached to the mature fruit; the androecium has at least two types of laminar poricidal stamens which shape is based on the locations (central versus peripherical), and the gynoecium is apocarpous. A mix of basal and derivative state of characters.