The aim of the article is to analyze the process of giving some semiotic status to a plant on the basis of its features; to demonstrate casual relationship between its appearance on the one hand and the phytonyms, superstitions, and rites on the other hand; to observe the ways of reflecting and semiotisation of their features (colour, smell, form) in traditional thought and creation. In this way it is possible to find some cognitive principles of including natural objects into cultural sphere, their place in cultural and language models of different traditions and, finally, ethnocultural peculiarities by analysing difference in such models. Here the ideas about several plants rather popular in the traditional Slavonic culture are analysed. In various local traditions they are named ivan-da-marja thanks to an unusual feature – combination of two colours. It became a basis for etiological legends about the plants and their ritual usage.