Characterization of two frequently confused species, Bonnemaisonia asparagoides and Bonnemaisonia clavata (Bonnemaisoniales, Rhodophyta), on the basis of morphological and molecular evidence

Abstract

N. Salvador, A. Gómez Garreta and M.A. Ribera Siguan. 2008. Characterization of two frequently confused species, Bonnemaisonia asparagoides and Bonnemaisonia clavata (Bonnemaisoniales, Rhodophyta), on the basis of morphological and molecular evidence. Phycologia 47: 177–190. DOI: 10.2216/07-24.1The similar morphology of Bonnemaisonia clavata and Bonnemaisonia asparagoides and the rarely reported vegetative and reproductive characters of the former have resulted in considerable difficulty distinguishing these two taxa as well as uncertainty concerning the taxonomic status of B. clavata. We have reassessed the relationship between these two species using both morpho-anatomical and molecular data. Observations on gametophytes confirm a suite of distinguishing features including structure of the thallus (monopodial vs sympodial), axial cell size, presence or absence of a spiral trichogyne, pericarp symmetry and number of carposporangia per cystocarp. Investigation of the ‘Hymenoclonium’ prostrate phase developed from cultured carpospores provided additional distinguishing characters including carpospore germination pattern and morphology of ‘Hymenoclonium’ developmental stages. The characteristics utilized by previous authors to distinguish B. asparagoides and B. clavata are discussed and evaluated. Partial chloroplast-encoded rbcL sequences for B. clavata and B. asparagoides were 7.66% different. This level of divergence supports the morphological evidence that B. clavata and B. asparagoides are distinct species.