Lactarius deliciosus sensu Hesler and Smith — Western saffron milk cap

Odour: Indistinct
Taste: Slightly acrid. (Briefly taste a pea-sized piece then spit it out.)
Cap: 5–15 cm in diameter, convex at first, expanding and developing a central depression. The colour is pinkish orange with concentric rings of lighter fibrils. Where bruised, the cap turns green. The surface is smooth, fibrillose when dry, slightly viscid when wet. Flesh of cap and stem are crisp when young and the mushroom breaks with a snap. The flesh is whitish with reddish-orange lines and flecks toward the outside where latex is being produced.
Gills: Crowded, attached or slightly decurrent, pinkish tan to orange, staining green, fragile.
Latex: Orange then staining green.
Stem: 3–4 cm long x 1.5–2 cm wide, straight and cylindrical or narrowing towards the base, hollow. The colour is initially mottled white and light pinkish orange and it becomes darker orange with age. If bruised, it turns green.
Ring or veil: None.
Cup: None.
Spores: 8–11 x 7–9 µm, with net-like, interconnected ridges.
Habitat: In coniferous forests. Ectomycorrhizal.
Geographical distribution: May be restricted to western North America. Due to confusion in the delimitation of similar species, the range extent of individual species is still unclear.

The Pacific northwest/BC species is not the same as the true European saffron milk cap 'Lactarius deliciosus'. We use the common name 'western saffron milk cap' for the North American 'Lactarius deliciosus' (in the sense of milk-cap specialists Hesler and Smith)4, a species that has yet to be formally described3. Lactarius aestivus is another of western North America's orange milk caps3. It differs from the western saffron milk cap in that the latex, although initially orange, stains green only slowly if at all. Host trees may also differ, with the western saffron milk cap tending to grow with pine (Pinus) or spruce (Picea), while Lactarius aestivus has been collected under fir (Abies) and hemlock (Tsuga)3. The bleeding milk cap Lactarius rubrilacteus also has an orangish cap and stem but it has red or brownish-red latex rather than orange latex. The latex of this species slowly turns bluish green. The bleeding milk cap is associated with Douglas fir (Pseudotsuga menziesii) rather than pine or spruce5. Additional species, all with orange fruitbodies with orange or pinkish red latex that turns green are also present in western North America but have yet to be described.

Although they are generally edible, the several western American orangish milk caps with orange or red, green-staining latex do not have extensive track records of human consumption. Opinions about their taste and texture vary, with some people considering them to be as delicious as the European name suggests. The related saffron milk cap (the true Lactarius deliciosus) is prized for its flavour in Spain6 and other European countries. Like other mushroom species, saffron milk caps can concentrate heavy metals and should not be eaten if harvested in contaminated sites7. Milk caps sometimes cause gastrointestinal upsets8.

Treatment11: Contact your regional Poison Control Centre if you or someone you know is ill after eating milk caps. Poison centres provide free, expert medical advice 24 hours a day, seven days a week. If possible, save the mushrooms or some of the leftover food containing the mushrooms to help confirm identification.

Poison Control:
British Columbia: 604-682-5050 or 1-800-567-8911.
United States (WA, OR, ID): 1-800-222-1222.

UBC. Mycology Collections Portal, <> March 2018.

Specimen Lactarius deliciosus sensu Hesler and Smith UBC F33058, GenBank #MH718243.

Nuytinck, J. & Ammirati, J. F. A new species of Lactarius sect. Deliciosi (Russulales, Basidiomycota) from western North America. Botany 92, 767-774, doi:10.1139/cjb-2014-0102 (2014).

Hesler, L. R. & Smith, A. H. Studies on Lactarius-I: The North American species of sect. Lactarius. Brittonia 12, 119-139, doi:10.2307/2805213 (1960).

Siegel, N. & Schwarz, C. Mushrooms of the Redwood Coast. A Comprehensive Guide to the Fungi of Coastal Northern California. Ten Speed Press, Berkeley, California (2016).

Diaz-Balteiro, L., Alfranca, O. & Voces, R. Market of Lactarius deliciosus. Modelling the supply in Spain. Itea-Informacion Tecnica Economica Agraria 109, 370-389 (2013).

Rubio, C. et al. Trace element and toxic metal intake from the consumption of canned mushrooms marketed in Spain. Environ. Monit. Assess. 190, doi:10.1007/s10661-018-6614-6 (2018).

Beug, M. W., Shaw, M. & Cochran, K. W. Thirty-plus years of mushroom poisoning: Summary of the approximately 2,000 reports in the NAMA case registry. McIlvainea 16, 47-68 (2006).