Do the Ophioglossales represent ferns as traditionally interpreted, or are they derived from progymnosperms, as hypothesized by Bierhorst (1971) and others (e.
Results of both the complete analysis [ILLUSTRATION FOR FIGURE 2 OMITTED] and the "extant only" analysis [ILLUSTRATION FOR FIGURE 4 OMITTED] support the Ophioglossales as a monophyletic group.
On the other hand, results obtained here [ILLUSTRATION FOR FIGURES 2 & 4 OMITTED] do not support the alternative hypothesis that Ophioglossales is derived from the progymnosperms, such as Archaeopteris (e.
Ophioglossales is a monophyletic group that forms the sister group to all other taxa of Fern Clade #3.
New character, reflecting the distinctive ontogeny/morphology of the foliar organs in the Ophioglossales (Bierhorst, 1971).