• Australia;
  • Brazil;
  • Laurencia dendroidea;
  • Laurencia majuscula;
  • rbcL;
  • Rhodomelaceae;
  • Rhodophyta


Morphological and molecular studies have been undertaken on two species of the red algal genus Laurencia J.V.Lamouroux: Laurencia majuscula (Harvey) A.H.S. Lucas and Laurencia dendroidea J.Agardh, both from their type localities. The phylogenetic position of these species was inferred by analysis of the chloroplast-encoded rbcL gene sequences from 24 taxa. In all phylogenetic analyses, the Australian Laurencia majuscula and the Brazilian L. dendroidea formed a well-supported monophyletic clade within the Laurencia sensu stricto. This clade was divided into two subclades corresponding to each geographical region; however, the genetic divergence between Australian L. majuscula and Brazilian L. dendroidea was only 0–1.35%. Examination of the type specimens and sequences of freshly collected samples of both Laurencia majuscula and L. dendroidea show the two to be conspecific despite their disjunct type localities.