formerly a taxonomic division or phylum, the group comprises a tremendous diversity of plants. Tracheophytes can be divided into two groups of seedless plants: the lycophytes (club mosses, spike mosses, and quillworts) and the ferns (including horsetails and whisk ferns); and two groups of seed-bearing plants: the gymnosperms (cycads, pines, spruces, firs, etc.) and the angiosperms (flowering plants). See bryophyte for plants that lack vascular systems.