Relationships of Lycopodium and Lycopodiella based on combined plastid rbcL gene and trnL intron sequence data

The relationships of Lycopodium and Lycopodiella (Lycopodiaceae) were inves tigated based on two plastid data sets (rbcL gene and trnL intron) from a r epresentative sample of 21 species. Separate and combined analyses of the d ata reveal consistent patterns of relationship. There is strong support for monophyly of Lycopodium and Lycopodiella. There is also support for monoph yly of species groups or sections sensu Ollgaard (Lycopodium, Diphasium, Ma gellanica, Complanata, Lycopodiella, and Campylostachys). The combined data provide new evidence of relationships between subgeneric groups. In Lycopo dium, section Pseudodiphasium groups with section Magellanica section Obscu ra groups with section Diphasium, and section Annotina groups with section Lycopodium. in Lycopodiella, sections Lateristachys and Caroliniana group w ith section Campylostachys and this group is sister to section Lycopodiella . Tentative calibration of the phylogenetic tree using fossil evidence indi cates a minimum age of Early Jurassic (208 Myr) for the split between Lycop odium and Lycopodiella. Reticulate fossil spores from Upper Permian records are potentially of Lycopodium affinity and indicate that early cladogenesi s in Lycopodium may be even older. An evaluation of biogeographic and phylo genetic patterns in these two genera shows a striking difference from that in Huperzia. Sections within Lycopodium and Lycopodiella have broad geograp hic distributions, whereas molecular data partition the much larger Huperzi a group into predominantly neotropical and paleotropical clades.