Toward a monophyletic Cheilanthes: The resurrection and recircumscription of Myriopteris (Pteridaceae)

Michael Windham,Amanda Grusz

doi:10.3897/phytokeys.32.6733

Abstract

The fern genus Cheilanthes (Pteridaceae) has perplexed taxonomists for more than two centuries. Complex patterns of evolution involving rampant morphological convergence, polyploidy, hybridization, and apomixis have made the taxonomy of this group especially difficult. Fortunately, recent phylogenetic analyses have helped to clarify relationships among cheilanthoid taxa. Based on these findings, we here formalize an updated taxonomy for one monophyletic clade comprising 47 primarily North and Central American taxa usually included in Cheilanthes. Because the type species of Cheilanthes (Cheilanthes micropteris) is only distantly related to this clade, we resurrect the genus Myriopteris to accommodate these taxa, and present a revised circumscription for the group, including 36 new combinations.

Highlights

A “practical and natural” generic classification of cheilanthoid ferns (Pteridaceae) has eluded taxonomists for more than 200 years and was viewed by Tryon and Tryon (1982) as one of the most contentious issues in fern systematics
The first option would require 400+ new combinations in Hemionitis. It would subsume a number of cohesive, well-characterized genera that are clearly distinct based on morphological, molecular, and cytological grounds, including Adiantopsis (Link-Pérez et al 2011), Argyrochosma (Windham 1987; Sigel et al 2011), Astrolepis (Beck et al 2010), Doryopteris (Yesilyurt 2004), Gaga (Li et al 2012), and Notholaena (Rothfels et al 2008). This approach would maximize the number of nomenclatural changes while simultaneously obscuring well-documented phylogenetic relationships, resulting in the inclusion of all but six cheilanthoid species in one genus
Myriopteris predates Cheilosoria by 25 years and, when these species are assigned to a single genus, Myriopteris is the correct generic name for the inclusive myriopterid clade

Summary

Launched to accelerate biodiversity research

Toward a monophyletic Cheilanthes:The resurrection and recircumscription of Myriopteris (Pteridaceae). Ranker | Received 2 December 2013 | Accepted 5 December 2013 | Published 19 December 2013 Citation: Grusz AL, Windham MD (2013) Toward a monophyletic Cheilanthes: The resurrection and recircumscription of Myriopteris (Pteridaceae).

Introduction

Historical use of the name Myriopteris

Taxonomic treatment

Findings

New and resurrected combinations in Myriopteris