In 1874, Farlow returned to Harvard and, with the support of Professor Gray, received an appointment as an assistant
professor of
botany at the
Bussey Institution in 1874. He became Professor of
Cryptogamic Botany from 1879 until his death 40 years later. Farlow retired from undergraduate teaching in 1896 but continued to advise graduate students, collect specimens, and conduct research. He willed his herbarium and library to Harvard, where they form the
Farlow Herbarium of Cryptogamic Botany. He published dozens of scientific articles, reports, and conference papers. In 1895, Farlow played a leading part in the creation of the New England Botanical Club, hosting a meeting at his
Cambridge, Massachusetts home to discuss forming an organization devoted to the study of the local
flora. After the club was established, he served as its first president. Through his teaching, publications, and help with specimen identifications, he also encouraged a circle of professional and amateur botanists whose work on algae,
bryophytes, lichens, and fungi appeared in the early volumes of
Rhodora. Farlow also built the collections that later formed the core of the Farlow Library and Herbarium of Cryptogamic Botany. Among the major collections he acquired were the herbaria of
Moses Ashley Curtis and
Edward Tuckerman, which together amounted to more than 60,000 specimens. He also preserved sets of
exsiccatae as intact published units rather than breaking them up, recognizing their
taxonomic and bibliographic value. He corresponded with other botanists such as
Caroline Bingham and
Jacob Georg Agardh and collaborated in the identification and classification of species of algae previously unknown to science. Two
genera, the algae
Farlowia and the fungus
Farlowiella, were named in his honor in 1876 and 1891, along with numerous species of algae, fungi, and lichens. He served as president of the
American Society of Naturalists in 1899, president of the
National Academy of Sciences in 1904,
president of the
American Association for the Advancement of Science in 1905, and president of the
Botanical Society of America in 1911. He was also a member of the
American Philosophical Society, a fellow of the
Linnaean Society of London, and a member of the
Paris Academy of Science. the
University of Wisconsin–Madison (LL.D, 1904), and
Uppsala University (Ph.D., 1907). == Personal life ==