XVI International Botanical Congess

A close relationship was been established between the members of Ulva and Enteromorpha (Ulvacea). The two green algal genera were shown to be monophyletic. Morphological characters that have conventionally been used for species identification were studied and mapped on to a phylogenetic tree. This tree was based on rDNA ITS and 5.8S gene sequence data of the same taxa. Within the monophyletic Enteromorpha-Ulva clade there were several well identified clades but only few of these corresponded to the morphological species that have been described within these genera. The majority of the mapped characters did not correspond to the position in the tree. No apomorphic characters were found for any of the clades. Enteromorpha and Ulva were shown to exhibit extreme morphological variation, on all taxonomic levels.