Botanist Arthur Louis Arthurovič Jaczewski served as director of the Plant Pathology section at the St. Petersburg Botanical Garden.

Jaczewski was born at his family's country estate, Ryklowa, in the province of Smolensk, west of Moscow. An aristocratic family, they spoke French at home, and Jaczewski chose to study in Switzerland at the University of Bern. Here he was introduced to mycology by Professor Eduard Fischer, which became one of his lifelong passions. Over the course of his career he would publish numerous monographs, manuals and scientific papers on the fungi and plant diseases of Russia.

Following his studies in Bern and after travels in France, Italy and Algeria, Jaczewski returned to Russia and completed his studies at Moscow University in 1887. In 1896 he established a laboratory for mycology and plant pathology at the St Petersburg Botanical Gardens, where he placed his private library and herbarium. A few years later, in 1901, the Ministry of Agriculture appointed him head of the new Central Laboratory of Plant Pathology, where he remained for the rest of his career, becoming director of the new Bureau of Mycology and Phytopathology in 1907.

In 1920 Jaczewski helped to found the Mycological Society of Russia and also a School of Phytopathological and Applied Zoology. In his honour, in 1927 the government named his laboratory at the Leningrad Academy of Agricultural Sciences, the Jaczewski Mycological and Phytopathological Institute.

Sources:
L.R. Jones, 1933, "Arthur Jaczewski", Phytopathology, 23: 111-116.