Vittarioideae worthy of subgeneric rank, while "Rheopteris" had not yet been discovered. "Haplopteris" he explicitly synonymized with "Vittaria" in 1914. Carl Christensen used the name "Vittarioideae" in Verdoorn's "Manual of Pteridology" in 1938, but did not include a description, leaving it nomenclaturally invalid. Ren-Chang Ching raised Vittariaceae to the rank of a family in 1940. The first well-sampled molecular phylogenetic study of the vittarioids was based on the chloroplast gene rbcL. In this study, it was found that the type species of "Monogramma" is embedded in "Haplopteris"; the segregation of "Vaginularia" from "Monogramma" was also supported, as members of "Vaginularia" formed
Evolutionary history of plants such as "Rhynia" preserved in the Rhynie chert is of similar complexity, which is taken to support this hypothesis. By contrast, with the exception of "Psilotum" modern vascular plants have heteromorphic sporophytes and gametophytes in which the gametophytes rarely have any vascular tissue. There is no evidence that early land plants of the Silurian and early Devonian had roots, although fossil evidence of rhizoids occurs for several species, such as "Horneophyton". The earliest land plants did not have vascular systems for transport of water and nutrients either. "Aglaophyton", a rootless vascular plant known from Devonian fossils in the Rhynie chert