The fungi generally identified as L. uvidus are part of a complex of closely related species and varieties which are difficult to delimit definitively.

[7] It appears classified as vulnerable or endangered in the Danish and Dutch Red Lists of Fungi.

[9][10] Lactarius uvidus belongs to section Uvidi of the genus, the members of which are characterized by milk which discolours violet, and by the greasy cap surface.

Some less well-known but closely related European species are L. pseudouvidus Kühner (1985) (found in alpine zone, up to 4 cm in diameter, with ochraceous yellow gills), L. robertianus Bon (1985) (also alpine, darker coloured, with smell of cedar wood), and L. luridus (Pers.)

Since L. uvidus seems to be a cluster of species, it is particularly difficult to pin down the correspondence between descriptions and collections originating from Europe (on one hand) and from North America (on the other).