17 June) 1835, Moscow – 8 December 1918, Petrograd) was a Russian botanist, public figure, and academician of the Petersburg Academy of Sciences (1884).

[1] Famintsyn attended Saint Petersburg State University and studied under Russian fungal expert Lev Semionovich Tsenkovsky.

Famintsyn is considered the founding father of the Petersburg School of plant physiologists (Ivan Borodin, Alexander Batalin, Dmitry Ivanovsky and others).

Famintsyn showed that carbon dioxide conversion by plants and formation of starch may occur under artificial lighting.

Famintsyn discovered the symbiosis of algae with radiolaria and he developed a theory of symbiogenesis, alongside Konstantin Mereschkowski.