Evidence from molecular data supports the close taxonomic relationship of the two North Pacific species Delesseria decipiens and D. serrulata with Cumathamnion, up to now a monotypic genus known only from northern California, rather than with D. sanguinea, the type of the genus Delesseria and known only from the northeastern North Atlantic. The transfers of D. decipiens and D. serrulata into Cumathamnion are effected. Molecular data also reveal that what has passed as Membranoptera alata in the northwestern North Atlantic is distinct at the species level from northeastern North Atlantic (European) material; M. alata has a type locality in England. Multiple collections of Membranoptera and Pantoneura fabriciana on the North American coast of the North Atlantic prove to be identical for the three markers that have been sequenced, and the name Membranoptera fabriciana (Lyngbye) comb. nov. is proposed for them. Many collections of Membranoptera from the northeastern North Pacific (predominantly British Columbia), although representing the morphologies of several species that have been previously recognized, are genetically assignable to a single group for which the oldest name applicable is M. platyphylla.Key Words: Cumathamnion; Delesseria; Delesseriaceae; Membranoptera; molecular markers; Pantoneura; Rhodophyta; taxonomy
INTRODUCTIONThe generitype of Delesseria J. V. Lamour. is D. sanguinea (Huds.) J. V. Lamour., a species occurring in the colder waters of the northeastern Atlantic Ocean, ranging from Arctic Norway and Iceland to Spain (South and Tittley 1986), as well as a reduced form extending into the Baltic Sea (Levring 1940, Nellen 1966, Lüning 1990. Its handsome image depicted by Oeder in Flora danica (1766, Pl. 349, as Fucus sanguineus) and reproduced in Wynne (2006) was based on a specimen collected in Iceland by Johann Gerhard König, a student of Linnaeus, in 1764-1765 and initially illustrated in the field by Helt, a young illustrator who accompanied König to Iceland. Helt's preliminary sketch was later refined in Copenhagen by Rösler (information from Peter Wagner, communicated by Ruth Nielsen, Copenhagen). Being a genus described so early (Lamouroux 1813), Delesseria has had numerous species assigned to it over the years. For example, J. Agardh (1872) assigned 48 species to his broadly defined Delesseria. Fifteen species are currently recognized in the genus (Guiry and Guiry 2012). This list of taxa now placed in DelesseriaReceived May 11, 2012, Accepted August 12, 2012 *Corresponding Author E-mail: mwynne@umich.edu Tel: This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
156(Hudson) Stackhouse, the generitype, has been recognized on both sides of the North Atlantic (Rosenvinge 1923-1924, Taylor 1962, Bird and McLachlan 1992, Maggs and Hommersand...