Friesian

A herd of Friesian cattle is grazing in a field in the British countryside.

[...] the more expensive and creamier Jersey or South Devon milk, for example, is kept apart from Friesian milk, with its low butter content.

For a hundred years, treatment of the basidiomycetes, which include so many of the larger fungi, has been dominated by the Friesian approach which had—and still has—the attraction of differentiating fungi into groups mainly on field characters.