XVI International Botanical Congess

Our knowledge of Takakia has expanded remarkably in the last decade with the discovery of both male and sporophytic plants in populations of T. ceratophylla from the Aleutian Islands and China. Since its establishment in 1958, this taxon has been the subject of considerable phylogenetic speculation. The vegetative gametophyte appears superficially to possess a blend of liverwort and moss characters, but developmental patterns as well as gametangial and sporophyte organizations support a closer affinity with mosses than with other embryophytes. Molecular sequence data support alignment of Takakia with the moss clade, but its relationships within the clade remain ambiguous. This paper will evaluate current phylogenetic hypotheses, using combined morphological, ultrastructural and molecular evidence.