Der Stammbaum der Ducks is a peculiar version of the Duck Family Tree written by Johannes A. Grote.
This version of the family tree contains several blatant mistakes, due to being based on the German translations of Barks's Disney comics, which contained, unbeknownst to Grote, several changes. The main oddity is that Scrooge McDuck and Donald Duck share the same family name in German; for that reason, the Duck family and the McDuck clan are treated as one and the same.
Nevertheless, Grote's tree also features a lot of interesting details and novel concepts. The main idea is that all portraits and photographs of anonymous ducks seen in indoor backgrounds by Carl Barks must be pictures of relatives. It is so that, for instance, the bearded duck portrait in A Descent Interval is retconned as Daisy's father Otto Duck. Still about the character Otto Duck, the tree also includes the idea of Donald Duck and Daisy Duck being cousins, as Otto Duck is also Donald's paternal uncle.