The Hawaiian Islands are well known for having one of the highest documented percentages of endemic plants in the world. Hawaiian ferns and lycophytes represent a relatively large percentage of the endemic flora with approximately 74% of the native fern and lycophyte species considered endemic. In addition, at least 40 taxa are naturalized aliens. We present a new synopsis of the Hawaiian fern and lycophyte flora that includes new state and island records, recent taxonomic updates and problems, and a summary of known and hypothesized geographical origins of fern and lycophyte lineages. We also provide a checklist and access to an interactive key to the native and naturalized ferns and lycophytes of the Hawaiian Islands ( http://www.herbarium.hawaii.edu/lucid/ferns/introduction.html).

Recent studies examining the evolutionary relationships of species assigned to Cheilanthes (Pteridaceae) reveal that the genus is highly polyphyletic. To achieve a monophyletic generic classification of the 400 taxa of cheilanthoid ferns, it is necessary to transfer species that are only distantly related to the type species (Cheilanthes micropteris) to other genera. One of these species is Cheilanthes villosa Davenp. ex Maxon, which needs to be reassigned to the genus Myriopteris. Because the epithet villosa is preoccupied in Myriopteris and there are no synonyms for this distinctive taxon, a new name is required. The species is herein renamed Myriopteris windhamii.

The genus Polystichum presents striking variation in morphology and habitat preference in the Central Andes, the Serra do Mar, and adjacent regions. Among these taxa, Polystichum montevidense is a name long applied to an array of twice-pinnate species with dark petiole scales, broad leaves, and no vegetative propagules. Using a classical morphological approach combined with inferences gleaned from molecular data, we analyzed P. montevidense and its widespread and ecologically prominent array of allies. Results from our combined molecular and morphological analysis suggest the name P. montevidense should be applied to collections from the Central Andes south to Argentina, and east to Uruguay and the southernmost portion of Brazil. Most Brazilian plants determined as P. montevidense in herbaria are P. platylepis.

The phylogenetic position of Dracoglossum Christenh. is studied here for the first time using DNA sequence data. Based on a broad sampling of eupolypod ferns and four plastid genes (atpA, atpB, rbcL, rps4), we show that Dracoglossum does not belong to the genus Tectaria Cav., in which it was previously placed, nor is it closely related to that genus or any other member of Tectariaceae. Our results provide strong support to suggest that Dracoglossum forms a rather isolated lineage, which is sister to Lomariopsis Fée, and that the genus should therefore be placed in Lomariopsidaceae.