Barnacle goose were of the same nature as other birds. The question of the nature of barnacle geese also came up as a matter of Jewish dietary law in the Halakha, and Rabbeinu Tam (1100–71) determined that they were kosher (even if born of trees) and should be slaughtered following the normal prescriptions for birds. The mythical barnacle tree, believed in the Middle Ages to have barnacles that opened to reveal geese, may have a similar origin to the other legends already mentioned. Barnacle goose The barnacle goose ("Branta leucopsis") belongs to the genus "Branta" of black geese, which contains species with
Apus (genus) Linnaeus in 1758. The name "Apus" is Latin for a swift, thought by the ancients to be a type of swallow with no feet (from Ancient Greek α, "a", "without", and πούς, "pous", "foot"). Before the 1950s, there was some controversy over which group of organism should have the genus name "Apus". In 1801 Bosc gave the small crustacean organisms known today as "Triops" the genus name "Apus", and later authors continued to use this term. Keilhack suggested (in 1909) that this was incorrect since there was already an avian genus named "Apus" by Scopoli in 1777 . It was