The evolution of land plants from green algal ancestors has long been a topic of interest to botanists and has more recently taken on special interest given results from molecular phylogenetic analyses. Parsimony and likelihood analyses were conducted on a data set comprising chloroplast rbcL, and nuclear, chloroplast, and mitochondrial small-subunit (SSU) rDNA (6095 total characters) from all major land plant lineages. Significant bootstrap support was obtained for 1) hornworts as sister to the remaining embryophytes, 2) a sister-group relationship between mosses and liverworts, and 3) monophyly of vascular plants, lycophytes, pteridophytes, seed plants, and angiosperms.. In contrast to the other genes, mitochondrial SSU rDNA analyzed alone recovered essentially the same topology as the multigene tree and had the lowest level of homoplasy. The tree topology obtained here is highly congruent with previous cladistic analyses of morphological characters, thus strongly suggesting that the same phylogenetic pattern is being tracked.

Key words: embryophyte, hornwort, liverwort, moss, rbcL, small-subunit ribosomal DNA