Armen Leonovich Takhtajan or Takhtajian (Armenian: ????? ????? ?????????; Russian: ????? ???????? ?????????; surname also transliterated Takhtadjan, Takhtadzhi?a?n or Takhtadzhian, pronounced TAHK-tuh-jahn) (June 10, 1910 – November 13, 2009), was a Soviet-Armenian botanist, one of the most important figures in 20th century plant evolution and systematics and biogeography.
His other interests included morphology of flowering plants, paleobotany, and the flora of the Caucasus.
He was born in Shusha.
He was one of the most influential taxonomists of the latter twentieth century.