A Unified Approach to Taxonomic Delimitation in the Fern Genus Pentagramma (Pteridaceae)

Journal Article (Journal Article)

The native goldback and silverback ferns of western North America, composing the genus Pentagramma, are phylogenetically isolated within the xeric-adapted cheilanthoid clade. Although species-poor compared to its sister group, Pentagramma encompasses a diverse array of morphotypes, cytotypes, and flavonoid chemotypes. Because the differences are generally cryptic, however, the various entities are usually recognized at an infraspecific level. In recent years, as many as five subspecies have been ascribed to P. triangularis, and only P. pallida has been considered sufficiently divergent to warrant recognition as a distinct species. In this study, we take a unified approach to taxonomic delimitation in Pentagramma. Combining spore studies with phylogenetic analyses of plastid and nuclear sequences, we identify six genetically and morphologically distinct diploid lineages, each of which is here treated as a species. A new species is described (P. glanduloviscida) and three new combinations are made (P. maxonii, P. rebmanii, and P. viscosa).

Full Text

Duke Authors

Cited Authors

  • Schuettpelz, E; Pryer, KM; Windham, MD

Published Date

  • September 2015

Published In

Volume / Issue

  • 40 / 3

Start / End Page

  • 629 - 644

Electronic International Standard Serial Number (EISSN)

  • 1548-2324

International Standard Serial Number (ISSN)

  • 0363-6445

Digital Object Identifier (DOI)

  • 10.1600/036364415x689366


  • eng