Circumscription and phylogeny of the Elaphoglossum ciliatum group (E. sect. Lepidoglossa, Dryopteridaceae) based on cpDNA sequences

Elaphoglossum (Dryopteridaceae) is one of the most diverse genera of ferns, yet it is noteworthy for lacking monographic studies for any of its subgroups. This study was an attempt to find a clade within Elaphoglossum with a convenient size for monographic study. The main goals were to determine what other species might belong to a clade of three species (E. burchellii, E. ciliatum, E. nigrescens) recovered by previous molecular analyses and to examine the phylogeny of the constituent species of that clade. Molecular data from three non-coding intergenic chloroplast spacers atpB-rbcL, rps4-trnS, and trnL-trnF, were used. The taxon sampling included 52 species of Elaphoglossum sect. Lepidoglossa. Maximum parsimony and maximum likelihood analyses resolved a ten-species clade (here named the Elaphoglossum ciliatum group), which included the three original species. Three of the species are endemic to the island of St. Helena in the southern Atlantic Ocean. The other seven species are all Neotropical, occurring from Mexico and the West Indies to southern Brazil. Species of the E. ciliatum group are characterized by laminar scales reduced to minute dots, cristate, echinate perispores, and resinous rhizomes. Other well-supported clades within E. sect. Lepidoglossa were recovered in the analyses and are briefly discussed.