This article discusses the motivation of the word "das Kraut/ das Gras - o‘t-grass" for the secondary nomination of plants in German and Uzbek and questions related to this motivation based on encyclopedic dictionaries. The word-formation analysis of plant names makes it possible to identify some regularities in the origin and word formation of plant nominations, to expand knowledge about some plants, to learn about particular cases of similarities and differences between phytonyms in German and Uzbek botanical nomenclature. The main idea of the author is that knowledge of the principle of the popular name of plants, which for the most part is an orientation to signs similar in appearance, helps to understand the specifics of the language and nationality.