The article deals with issues of phytonyms, i.e. with proper names of plants, especially with dendronyms – names of trees – as one of subsidiary groups of names. In Czech onomastics, close attention has not been paid to phytonyms so far. The first part of the article focuses on defining the group of phytonyms and especially on dubious aspects of this issue – in linguistic, non-onomastic works, phytonyms often include appellative names of plants (jahoda – strawberry), dendronyms often include appel-lative names of trees (buk – beech), similar approach can be found in other Slavonic languages as well as in onomastic works written in German. Attention is also paid to discussions on names of plant varieties, on the borderline of chrematonyms and phytonyms. The second part of the article is focused on several extensive online databases of Czech dendronyms and indicates possibilities of further research in this field.