Grateloupia huanghaiensis sp. nov. (Halymeniaceae, Rhodophyta), a peculiar new species from China

Abstract

Grateloupia huanghaiensis sp. nov. is newly described on the basis of morphological observations and molecular analyses. We document the vegetative and reproductive structures of G. huanghaiensis, which show that the carpogonial ampullae and auxiliary cell ampullae are of the simple Grateloupia-type. The new species can be distinguished from other Grateloupia species by (1) compressed and sword-like apices; (2) being single or double pinnately branched; (3) axes and branches densely covered with numerous short proliferations; (4) numerous distichous or lateral branchlets with proliferations from either end of the thalli; (5) two- to four-layered cellular cortex; (6) densely and irregularly intertwined medullary filaments; and (7) reproductive structures scattered over the surface of branches. Analysis showed this new species to be embedded within the Grateloupia clade in ribulose-1,5-bisphosphate carboxylase/oxygenase gene (rbcL) trees. Morphological observations and molecular analysis support G. huanghaiensis as a new species.