Finnish plant physiologist. Fredrik Elfving's father was a well-known physician and, likewise, the son began to train for a career in medicine. At the University of Helsinki he was taught by the eminent bryologist S.O. Lindberg and took an interest in the cryptogamic plants. As a child he had taken the time to get acquainted with the plants of the region. This included the mosses, lichen and algae, which he studied using a microscope his parents gave to him on his 15th birthday.

At 20 years old he gained his candidate in philosophy degree, allowing him to enter the medical faculty, but after a few years he gave up the idea of practising as a physician. In 1875 he had travelled to Russian Karelia in order to study the plants of the region and in 1878 he embarked upon his official botanical training. Moving to Germany he studied cytology in Jena and then, in Würzburg with J. von Sachs, Elfving conducted laboratory research which he would use for his doctoral thesis on his return to Finland. In 1881 he was named docent of botany at the University of Helsinki and, at the death of Lindberg, Elfving took over the professorship in 1889. In between these years he had taken two further study trips to Europe, visiting famous botanical figures in Strasbourg, Copenhagen, Utrecht and Paris.

During his time as a lecturer at the university, Elfving revolutionised the way in which botany was taught in Finland. Not only did he start classes for complete beginners, but he also branched out from the confines of taxonomy (in which lessons had traditionally been held) and introduced plant physiology as a major part of the course. A lively and enthusiastic teacher he began practical microscopy classes and also offered lectures in diverse topics such as organography and seed taxonomy. For his students and for the general public, he wrote several major text books, such as Förare genom Växthusen I Helsingfors Botaniska Trädgård (1904), a guide to the Helsinki region. Elfving was, however, very strict when it came to examinations and he demanded much higher standards from his pupils (in the classroom and in the field) than other professors before him. Another great achievement of Elfving's at the university was to push through the creation of a new, and much needed, botanical institute, which was established in 1903.

As a researcher he covered a wide range of topics, including phytogeography, the algal family Desmidiaceae, cultivated plants and the history of learned societies in Finland. The field in which he made the largest contribution, though, is that of plant physiology. For his doctoral thesis Elfving had studied rhizomes and their orientation and he continued to produce bold new theories from his experimental work with mixed results. In 1882 he published seminal work on the flow of water through ligneous stems, coming to the conclusion that water flows through the lumina of the vessels, not through its walls. Today this seems as expected, but at the time it was generally accepted that the walls of stem vessels carried water. For many years after this he continued research into the reaction of plants and fungi to certain stimuli, including electrical currents and metals.

Elfving held on to his intuitions and followed them with conviction, a trait which led him to support two erroneous theories which he espoused in later life. One was that Aspergillus and Penicillium could change, over time, into yeast and later, mould. The second, which he considered his most important finding, was his 'disproval' of Schwendener's theory that lichens have a dual nature: algae and fungi. Elfving was adamant that this could not be, and instead he championed a theory which would have crumbled the very foundations of cryptogamic botany. Although he was widely criticised, Elfving fearlessly stood by his ideas.

In 1926 he retired from the university and he was keenly involved in the Finnish Naturalists Society (Societas pro Fauna et Flora Fennica), acting as their secretary between 1923 and 1934 and later as honorary president.

Sources:
R. Colander, 1965, The History of Botany in Finland.