The anther structure of Bromeliaceae Juss. (Poales) in an evolutionary perspective

Abstract Although the androecium provides diagnostic characters, as well as insights into reproductive strategies in Bromeliaceae, the anther has historically been neglected in comparative studies. This research aims to explore the structural evolution of the anther in Bromeliaceae within a comprehensive phylogenetic framework. We analysed representatives from 40 genera across the eight subfamilies, using standard light microscopy and microtechnique methods. Ancestral traits were reconstructed using maximum parsimony and maximum likelihood applied on a consensus supertree. Twenty-five variable characters were described and compared. Our data indicate that short oblongoid, dorsifixed, and introrse anthers are ancestral in Bromeliaceae, while basifixed and latrorse anthers, whether lanceoloid or linear, are derived characters. Regarding the anatomy, it was conservative among groups. The connective characters are the most informative and variable. This structure is ancestrally reduced to a few layers of parenchyma with a tabular endothecium that is also plesiomorphic. The reduction of the tabular endothecium occurred independently multiple times, being expanded only in species of Dyckia. The consequences of these characters for anther dehiscence and other reproductive traits are discussed within the evolutionary context of the family. The newly examined characters provide unprecedented data for understanding the evolution of reproductive structures and offer a valuable resource for Bromeliaceae systematics.