Pteridophytes or Pteridophyta, in the broad interpretation of the term (or sensu lato), are vascular plants (plants with xylem and phloem) that reproduce and disperse via spores. Because they produce neither flowers nor seeds, they are referred to as cryptogams. The group includes ferns, horsetails, clubmosses, spikemosses and quillworts. These do not form a monophyletic group, because ferns and horsetails are more closely related to seed plants than to lycophytes (clubmosses, spikemosses and quillworts). Therefore, pteridophytes are no longer considered to form a valid taxon, but the term is still used as an informal way to refer to ferns (monilophytes) and lycophytes, and some recent authors have used the term to refer strictly to the monilophytes.