Maak Richard Karlovich - teacher and researcher of Siberia (1825-1886), studied at St. Petersburg. univ.; was a teacher, director of schools in Irkutsk province., Chief inspector of schools in Eastern Siberia, member of the council of the Ministry of Education; made a number of important expeditions - to the Vilyui district (1854-55), to the Amur Territory (1855-56) and to the valley of the river. Ussuri (1859-60). His work contributed to the knowledge of the flora of the Amur and Ussuri countries.