Morphological Phylogenetics of Quesnelia (Bromeliaceae, Bromelioideae)

The genus Quesnelia presently includes 18 species, which occur mainly near the east coast of Brazil from the states of Rio de Janeiro to Bahia. The genus has been divided into two subgenera, Quesnelia and Billbergiopsis. However, its generic and subgeneric delimitation is artificial: in several classifications proposed in the family, different investigators have questioned the naturalness of the group, noting its affinity with species of Aechmea and Billbergia. With the objective of assessing the monophyly of the genus, and evaluating the subgeneric delimitation and the relationship of its species to other genera, a phylogenetic analysis was carried out based on parsimony. The analysis included 33 taxa, with 92 morphological characters. The genera Quesnelia and Aechmea emerged as polyphyletic, and Billbergia as monophyletic. In regard to the subgeneric classification, Quesnelia subgenus Quesnelia emerged as monophyletic, and Quesnelia subgenus Billbergiopsis as polyphyletic. The majority of the species of Quesnelia subgenus Billbergiopsis emerged as the sister group to Billbergia. Even when anatomical and palynological characters were included, the consistency index of the tree obtained was low, indicating high levels of homoplasy. In addition, the majority of clades did not have good statistical support. Therefore, taxonomic changes are not proposed because these would be premature.