Lactarius deterrimus, commonly known as Orange Milkcap, is a medium to large agaric with a smooth stem and pale carrot-coloured gills. It exudes orange milk that stains green. While it bears similarities to Lactarius deliciosus, there are several notable distinctions. Lactarius deterrimus prefers spruce trees instead of pines, its stem lacks pot-holes, and its cap typically exhibits fewer zoning patterns and is more prone to green staining. It can be found growing individually or in scattered groups throughout the soil under conifers, particularly spruce trees.

Cap first round with a slightly depressed centre and rolled-in margin. Then shallow to funnel-shaped. The colour is yellowish orange zoned with darker areas and nearly always with irregular green patches. It is sticky or slippery when wet. Gills dense and slightly extending downward. Same colour as the cap. Stem similar in colour as the cap, smooth, tough, but at the same time delicate and fragile. The stem has no ring. Flesh dirty gray colored. It turns orange at the edges because of the carrot-coloured milky liquid that escapes when broken. Spore print pale pinkish buff.

Microscopic Features: The spores measure 7-10 x 6.5-7.5 µm and have an ellipsoid shape. They are ornamented with amyloid warts and ridges that extend up to about 0.5 µm in height. Fairly frequent connectors form partially reticulate patterns.

Lactarius deterrimus on the First Nature Web site.
Lactarius deterrimus on the MushroomExpert.Com Web site.