XVI International Botanical Congess

Basal streptophytes occupy a pivotal position for understanding the diverstification of land plants. Synapomorphies of the clade include motile cell and mitotic features. Analyses of nucleotide sequences and intron data support monophyly of streptophytes. Charophycean algae are a paraphyletic grade basal to embryophytes, and molecular data place the Colechaetales sister to or closely related to the embryophyte clade. Within embryophytes, te mosses, liverworts, and hornworts are not supported as a monophyletic clade. Data from 18S and rbcL, intorns, and morphology provide conflicting hypotheses for the phylogenetic placement of charophycean groups, for the identities of the basal-most embyophyte group, and sister taxon of tracheophytes. Future work must sample more taxa and gene, add data on structural genomic features, and improve alignments.