Generic boundaries and phylogeny of Campylaephora (Ceramiaceae, Rhodophyta), including Campylaephora californica (Farlow) comb. nov.

Abstract

T.O. Cho, M.H. Hommersand, B.Y. Won and S. Fredericq. 2008. Generic boundaries and phylogeny of Campylaephora (Ceramiaceae, Rhodophyta), including Campylaephora californica (Farlow) comb. nov. Phycologia 47: 321–333. DOI: 10.2216/07-75.1

The four described species in the genus Campylaephora J. Agardh, tribe Ceramieae, namely, C. hypnaeoides, C. borealis, C. crassa and C. japonica, are known only from the western North Pacific. A new combination, C. californica, is proposed for plants referred to as Microcladia californica, originally described from syntype localities of California and Oregon. The species has alternate branching, six or seven periaxial cells per axial cell, internal rhizoidal filaments derived from periaxial and cortical cells, spermatangia formed from outer cortical cells, tetrasporangia developing from periaxial and inner cortical cells and covered by outer cortical cells, and naked carposporangia without involucral branchlets. Campylaephora is redefined to include species characterized by the presence of multiple layers of rhizoidal filaments derived from cortical cells that are linked by secondary pit connections. In our molecular study inferred from plastid-encoded rbcL sequence analysis, C. californica from San Mateo, California, nested inside the Campylaephora clade with strong bootstrap support and was separate from a Microcladia species. Our molecular phylogenetic analyses also revealed that C. californica is a separate entity among the species of Campylaephora. The genus Campylaephora forms a terminal clade within the tribe Ceramieae. Ceramium boydenii is basal in rbcL trees leading to Campylaephora and less advanced in possessing single-layered cortical rhizoidal filaments that lack secondary pit connections.

Key Words::

• Campylaephora
• Campylaephora californica
• Ceramiaceae
• Phylogeny
• rbcL
• Rhodophyta
• Taxonomy

ACKNOWLEDGMENTS

This work was supported by the research fund Chosun University 2008 to Tae Oh Cho and NSF PEET grant DEB-0328491 to S. Fredericq & M.H. Hommersand.