From the 'Dictionary of First Names in Current Use in Poland' (Rymut 1995) I isolated a group of names that can be connected with the common names of plants. According to ethnographers plants have an apotropaic power (warding off evil, protective) applied against demons. In connection with this, names of plants could appear in the function of protective names. I divided the names I noted down from the 'Dictionary of First Names' into three groups. The first group in the dictionary are those motivated by appellatives (names of plants) and transferred into the category of personal names. In the second part of the dictionary there is a group of plant names which were created from given names, which happened as a result of appellativization. The third group of names in the Dictionary consisted of so-called eponyms, or words created from the given name or surname of a real or fictitious person, e.g. the appellative dalia (the name of a flower) comes from the surname of the botanist Anders Dahl. The personal name Dahl passed from the category of proper nouns to the category of appellatives, and became the name of the appellative dalia, thereby changing its function and semantics. Subsequently dalia passed from the class of appellatives into the class of proper nouns, and became a personal name once more -the given name Dalia. We are dealing here first and foremost with a process of appellativization, later of onymization. Given names are proper nouns; in some situations, however, they undergo appellativization. In their secondary function they can become names of plants, through which they gain a new significance. In turn, some plant names, as a result of onymization with changes in semantics and function, can become personal names.