Phylogeny and character evolution of the neotropical fern genus Cyclodium (Dryopteridaceae)

<p><em>Cyclodium</em> is a neotropical fern genus with 13 species, most of them distributed in the Amazonian lowlands, particularly in the Guianan region and along the border with the Andes. It belongs to the polybotryoid clade of Dryopteridaceae, being unique within this clade by a combination of characters related to rhizome growth, leaf dimorphism, anastomosing venation, and peltate indusia. Here we present a molecular phylogenetic hypothesis for <em>Cyclodium </em>resulting from Bayesian and Maximum Likelihood analyses, using molecular sequences of five plastid markers. We also map 12 morphological characters and habit onto the resulting trees. Our results support <em>Cyclodium </em>as monophyletic and sister to <em>Polybotrya</em>. The presence of peltate indusia is the main character distinguishing <em>Cyclodium</em>. Our results also suggest that plesiomorphic conditions in <em>Cyclodium </em>are free venation (vs. anastomosing), creeping rhizomes (vs. erect or decumbent), highly dissected laminae (vs. 1-pinnate), monomorphic sterile and fertile fronds (vs. dimorphic), and pinnatifid apices (vs. conform).</p>