Maciel et al. 2018 (Article) Aechmea

Polyphyly and morphological convergence in Atlantic Forest species of Aechmea subgenus Chevaliera (Bromeliaceae)

Author(s):—J.R. Maciel, A.M. Benko-Iseppon & M. Alves

Publication:—Botanical Journal of the Linnean Society 20: 1–15. (2018)

Abstract:—A better understanding of the phylogenetics of Aechmea subgenus Chevaliera is hampered by the limited taxonomic
sampling in molecular studies of Bromelioideae. To test the monophyly of Aechmea subgenus Chevaliera, we conducted
a molecular phylogenetic study using three DNA regions (ETS, matK and phyC) and a reconstruction of ancestral
states of morphological characters. Our sampling included 22 of the up to 30 species recorded in the subgenus.
Aechmea subgenus Chevaliera turned out to be clearly polyphyletic, with Amazonian species previously included
in A. subgenus Chevaliera being found in separate clades of the phylogenetic tree for Bromelioideae. Two distinct
groups comprise the majority of the Atlantic species up to now grouped in Chevaliera. The first of these, referred to as
the A. multiflora group, includes seven species related to A. multiflora. The second group includes 11 species, referred
to as the A. sphaerocephala group. Morphological analyses show that the A. multiflora and A. sphaerocephala groups
are convergent in plant size, growth form and inflorescence morphology. The groups can morphologically be best
differentiated based on the margin of the floral bracts and petal colour.

Keywords:—romelioideae – evolution – floral bracts – flower – inflorescence – plant size – taxonomy