Morphological and Molecular Evidence Supports Recognition of Austrochondria Gen. Nov. (Rhodomelaceae, Rhodophyta) for the Chilean Endemic Laurencia chilensis

Abstract

Many red algal species described solely from morphology have historically been assigned to inappropriate genera because of superficial morphological similarity. Laurencia chilensis, originally described for specimens from Chile, has long been recognized as the only representative of Laurencia in Chile, but its systematic position is still understudied. We examined morphology of syntype material and specimens collected in the present study and analyzed rbcL sequences from our collections. One syntype specimen (De Toni herbarium no. 63) is here designated as the lectotype of L. chilensis. Laurencia chilensis specimens possess five pericentral cells per axial segment and plate-like spermatangial branches with sterile marginal cells, typical of the tribe Chondrieae. The rbcL sequences we obtained were identical and recovered the Chilean specimens as a strongly supported, distinct lineage from Chondria and other genera within the Chondrieae. Accordingly, we propose Austrochondria chilensis gen. et comb. nov. This study resolves the long-standing taxonomic position of this Chilean endemic and contributes to a more natural classification of the Chondrieae.