Larkin KennedyA Phylogenetic Analysis of Moonwort Species (Botrychium s.s.)
Using Three Plastid DNA Sequence Data Sets
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Botrychium s.s., commonly called moonworts, although widespread through most of the world, are small plants and are often difficult to identify just by physical features. Above ground, moonworts are composed of a single leaf, divided into the reproductive (fertile) and non-reproductive (sterile) portions. Because of the small size and relatively simple form of the leaves, there are few morphological characters present that are useful for distinguishing species and constructing classifications. Molecular and genetic data have been useful for distinguishing the 27 North American moonwort species. Previous plastid DNA sequence analyses of 21 moonwort species showed that eight polyploid species have a similar or identical rbcL gene as their chloroplast parent. For this project, we sequenced the chloroplast rpL16 region for 24 moonwort species. For three species not previously sequenced, B. pallidum, B. boreale, and B. gallicomontanum, rbcL and trnL-F sequences were obtained. Analysis of the rpL16 dataset supported species relationships established in the rbcL and trnL-F phylogeny. Three well-supported clades were identified: Lanceolatum (nine species), Lunaria (two species), and Simplex-Campestre (13 species). Simplex-Campestre and Lunaria clades were sister, and these two were sister to the Lanceolatum clade. Autapomorphic substitutions in the rpL16 sequences for species of the Lanceolatum and Lunaria clades were consistent with current species delimitations. Within Simplex-Campestre clade, combined analyses indicated that the Pallidum and Simplex subclades are sister, while members of the Minganense subclade did not group with any known diploid species and their diploid progenitor is either unknown or extinct.