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
The Power of Movement in Plants the work. The work was begun in earnest late in 1877, after his work on climbing plants (1875) and insectivorous plants (1875) stimulated his interest in the subject. At times, Darwin despaired of ever finishing the work, as the book outgrew his original expectations: As the book neared completion, he summarised its underlying viewpoint: The work concerns itself with how plants respond to external stimuli and examines these processes in individual plants to gain understanding of some general principles governing their growth and life. This continues Darwin’s work of elucidating how natural selection works and specifically how plants have adapted