1 October 2001 Phylogenetic Placements of Loxoscaphe thecifera (Aspleniaceae) and Actiniopteris radiata (Pteridaceae) Based on Analysis of rbcL Nucleotide Sequences
Gerald J. Gastony, William P. Johnson
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Nucleotide sequences of the chloroplast-encoded rbcL gene were determined for Loxoscaphe thecifera and Actiniopteris radiata and used in maximum parsimony cladistic analyses to determine their phylogenetic positions in the context of a broad range of advanced fern taxa. Loxoscaphe nested firmly within the Aspleniaceae, and Actiniopteris was placed with Onychium in the Pteridaceae. To help resolve conflicting contemporary treatments that either subsume Loxoscaphe species within Asplenium or segregate them as an independent genus, the rbcL sequence of L. thecifera was subjected to a more focused analysis involving all rbcL sequences available to represent the taxonomic diversity of Aspleniaceae. Loxoscaphe thecifera was sister to Asplenium griffithianum prolongatum, robustly and surprisingly nested within the clade of Asplenium species recognized as Asplenium section Thamnopteris, a group accepted by some as the segregate genus Neottopteris. These results indicate that there is presently no phylogenetic justification for accepting Loxoscaphe as a genus independent of Asplenium. Similarly Actiniopteris radiata, recently moved from the cheilanthoid to the taenitidoid group of Pteridaceae, was subjected to a more focused analysis in the context of an expanded set of cheilanthoid and taenitidoid species that included the first use of an rbcL sequence from the genus Anogramma and newly sequenced species of Onychium and Pteris. Actiniopteris is robustly grouped with two Onychium species in a clade sister to traditional taenitidoids and deeply separated from the cheilanthoids, supporting affinities previously suggested by spore morphology.

Gerald J. Gastony and William P. Johnson "Phylogenetic Placements of Loxoscaphe thecifera (Aspleniaceae) and Actiniopteris radiata (Pteridaceae) Based on Analysis of rbcL Nucleotide Sequences," American Fern Journal 91(4), 197-213, (1 October 2001). https://doi.org/10.1640/0002-8444(2001)091[0197:PPOLTA]2.0.CO;2
Published: 1 October 2001
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