According to Howard S. Reed (1942, 3), “among the events of the nineteenth century which indicated the impetus given to biological studies by the publication of Darwin’s Origin of Species (1859) none was more significant than the rise of international congresses.” Indeed, international congresses were a “symbol of the new freedom that science found after the emergence of the great ideas presented by Darwin.” For the botanical sciences, the introduction of Darwin’s theory of descent with modification created new challenges and fostered key developments that forever altered its practices. The world was expectant of new discoveries, the integration of ideas, the unification and simplification of terminologies, improvements in record keeping and documentation, and frequent international gatherings to present ongoing or novel programs of research to the larger community of botanists (see Reed 1942). This essay examines key movements and figures in the botanical sciences from the years between the 1880s and the 1920s, highlighting the impact of Darwin on the botanical sciences.

Darwin’s Botany by 1880

Botany provided key evidence to support Charles Darwin’s argument for descent with modification in the Origin of Species (1859), stemming from botanical experiments and observations by Darwin himself, as well as research from plant breeders such as T. A. Knight, plant distribution information from the Candolles, and advice from Joseph Dalton Hooker (Morton 1981, 415). Once the Origin of Species was completed in 1859, Darwin’s attentions were focused increasingly on botanical subjects, including publications on the fertilization of orchids (1862), climbing plants (1865), insectivorous plants (1875), fertilization (1876), flowers on plants of the same species (1877), and in 1880 the power of movement in plants.