At least in Europe
Cap 2.5-5.5 cm diameter; stem 3-7 cm tall x 0.5-1 cm diameter
Lactarius mammosus is a largish agaric that has a gray cap and pale gills and stem and exudes white milk. It grows solitary or in scattered groups on boggy soil under coniferous trees, mainly pine.
Cap convex, later flattening or with a depression, sometimes with a fiat to pointed umbo, margin at first somewhat inrolled; brownish, vinaceous-grey to umber or hazel, sometimes with one or more concentric bands; moderately thick, firm, surface dry, of feathery, adpressed fibres breaking into small, low, fibrous scales. Gills adnate to slightly decurrent, crowded; rosy buff, later darker with an orange tinge. Milk white; taste mild, then hot or very hot, smell of coconut.Spores Spore print cream. Flesh whitish to buff. Stem whitish or tinged with the cap colour, bruising pale cinnamon-brown. It has no ring.
Similar species Lactarius rufus which has more brown color and Lactarius trivialis which exudes transparent milk.