Verbruggen, H., De Clerck, O., N'Yeurt, A.D.R., Spalding, H. & Vroom, P., 2006
Verbruggen, H., De Clerck, O., N'Yeurt, A.D.R., Spalding, H. & Vroom, P. (2006). Phylogeny and taxonomy of Halimeda incrassata, including descriptions of H. kanaloana and H. heteromorpha spp. nov. (Bryopsidales, Chlorophyta). European Journal of Phycology 41(3): 337-362.
The tropical green algal genus Halimeda is one of the best studied examples of pseudo-cryptic diversity within the algae. Previous molecular and morphometric studies revealed that within Halimeda section Rhipsalis, Halimeda incrassata included three pseudo-cryptic entities and that the morphological boundaries between H. incrassata and Halimeda melanesica were illdefined. In this paper, the taxonomy of H. incrassata is revised: two pseudo-cryptic entities are described as new species, Halimeda kanaloana and Halimed heteromorpha, while H. incrassata is redefined to encompass a single, monophyletic entity. Similarities and differences between the three species and H. melanesica are discussed. Monophyly of H. heteromorpha, which was questioned in a former study, is reinvestigated using sets of 32 ITS1ITS2 and 21 plastid rps3 sequences and various alignment and inference methods. The phylogenetic relationships within Halimeda section Rhipsalis are inferred from nuclear 18SITS15.8SITS2 and concatenated plastid sequences (tufA & rpl5rps8infA) and interpreted in a biogeographic context.