Grateloupia Serra sp. nov. H. W. Wang & Y. Lou (Halymeniaceae, Rhodophyta): a new species previously confused with Grateloupia asiatica in China

Abstract

ABSTRACTA new Grateloupia species from Luxun park, Qingdao Province, North China, was discovered during recent investigations and named Grateloupia serra H. W. Wang & Y. Lou sp. nov. Morphological observations showed that: (1) the thalli were purple to dark red, cartilaginous and mucilaginous in texture, 15–45 cm in height; (2) the surface of thalli was covered with numerous proliferous branchlets and proliferous branchlets that were dentate when on the main axes; (3) the thalli were 450–550 µm thick, a cortex consisted of 6–8 layers of oblong or rounded cells and a medulla covered by compact medullary filaments; (4) the carpogonial branch was 6-celled and the auxiliary-cell branch was 5-celled, they were typical Grateloupia-type; (5) the internal structure of mature tetrasporangia were cruciately divided, oblong or square in shape. The morphological differences were supported by molecular analyses based on ribulose-1, 5-bisphosphate carboxylase/oxygenase gene (rbcL) sequences. Sequences of four G. serra sp. nov. samples were embedded into the Grateloupia clade and showed no pairwise divergence.