title: Misleading morphologies and the importance of sequencing type specimens for resolving coralline taxonomy (Corallinales, Rhodophyta): Pachyarthron cretaceum is Corallina officinalis.
abstract: Coralline red algae play a key role in the ecology of near shore marine ecosystems and are increasingly being used to study the effects of climate change in the marine environment. Corallines are very difficult to identify to species, and even to genus, using morpho-anatomy, likely complicating studies of their ecology, physiology, and biodiversity. We sequenced a 296 base pair fragment of chloroplast DNA from a 187-year-old isolectotype specimen of Pachyarthron cretaceum, a morphologically distinct geniculate species, to demonstrate that coralline morphology is often misleading and that species names can only be applied unequivocally by comparing DNA sequences from type material with sequences from field-collected specimens. Our results indicate that Pachyarthron cretaceum is synonymous with Corallina officinalis.
authors.affiliation: Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1Z4.
authors.forename: Katharine R
authors.initials: KR
authors.lastname: Hind
authors.affiliation: Herbarium and Biology Department, University of North Carolina - Chapel Hill, Coker Hall, CB 3280, Chapel Hill, North Carolina, 27599-3280, USA.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Gabrielson
authors.affiliation: Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1Z4.
authors.forename: Sandra C
authors.initials: SC
authors.lastname: Lindstrom
authors.affiliation: Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1Z4.
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Martone
keywords: geniculate coralline algae; historical DNA; systematics; taxonomy; type specimen