The names for the flowering plants Buddleja davidii, Sambucus nigra and Syringa vulgaris show a partial overlap in Dutch and German dialects. Flieder has the most diverse use and is geographically complementary to Holunder in German dialects. There is a horizontal border between the two, to the north of which Flieder is the name for Sambucus nigra, in Low German and most Dutch dialects; to the south the name usually refers to Buddleja davidii, namely in High German dialects and in the southeasternmost dialects of Dutch: Limburgian. Flieder and Holunder are also frequently (part of) the names for other unrelated plants, e.g. Syringa vulgaris, which is known in Dutch as sering. The close relationship between these three types of names and these three species of plants is hard to explain: there is no real etymological link and the unrelated species are only similar in part.