ziemniak (Polish) comes from Polish ziemny, from Proto-Slavic zemьnъ, from Proto-Slavic zemь, from Proto-Balto-Slavic źemē, from Proto-Indo-European ǵʰðʰem-, from Proto-Indo-European dʰéǵʰōm, from Proto-Indo-European -ōm, from Proto-Indo-European -mi.