What You Should Know
Lactarius scrobiculatus produces large agaricoid fruiting bodies which arise from soil. The cap has an eye-catching orange to yellow coloration and is covered with small scales arranged in indistinctive concentric rings. The surface is wet, glossy and slimy, especially in wet weather.
The cap may be wide, with a large diameter (about 15 cm in mature specimens), but with a depressed center and slightly inrolled margin.
The gills are crowded and colored cream to yellow, with darker patches being present sometimes. When cut, the gills bleed copious amounts of white to cream milk (latex), which soon darkens to yellow. The stem, with the cap, is quite short and stubby.
When a small piece of flesh is chewed, it tastes bitter to acrid. So acrid, that a researcher reportedly developed numbness in the mouth, having nibbled on a piece. It doesn't have any discernible smell.
Lactarius scrobiculatus is a basidiomycete fungus, belonging to the genus Lactarius, whose members are called "milk caps." Taxonomy places this species into subgenus Piperites, section Zonarii, subsection Scrobiculati. The distinctive fruiting bodies of this large fungus are locally common in forests throughout Europe and North America. It is regarded as inedible by some authors, but it is nevertheless eaten in parts of Europe.
Lactarius scrobiculatus Mushroom Identification
Mycorrhizal with conifers; growing alone, scattered, or gregariously; summer and fall; widely distributed in northern and montane regions of North America.
4-12 cm; broadly convex with an inrolled and bearded margin when young, becoming shallowly vase-shaped, with the margin uplifted and smoother; slimy when young, but soon dry; covered with fibers that may darken to brownish, the fibers remaining visible in maturity; whitish at first, becoming olive buff or yellowish in age; without concentric zones of color.
Beginning to run down the stem; crowded; often forking near the stem; whitish; bruising or staining yellowish to pale brownish.
3-11 cm long; 1-3.5 cm thick; equal; with many glazed, yellowish or brownish potholes; whitish; bruising and discoloring yellowish or brownish.
White, promptly turning yellow on exposure to air; scanty.
Odor and Taste
Odor not distinctive; taste mild or slowly slightly acrid.
White or creamy.
Spores 7-9 x 5.5-7 µ; ellipsoid; ornamentation about 0.5 µ high, as amyloid warts and scattered short ridges that occasionally branch but do not form reticula. Pleuromacrocystidia scattered; fusoid, often with an apical constriction; to about 80 x 12 µ. Cheilocystidia similar but shorter. Pileipellis an ixocutis with occasional fascicles of upright hyphae.
Lactarius scrobiculatus Similar Species
Produces latex that turns lilac; its spores are larger.
Has a pale pink to pinkish-orange woolly cap and grows under birches usually in damp soil.
Has a buff-white or cream woolly cap and grows mainly in damp grass under birch trees.
Lactarius scrobiculatus Edibility
Most authors consider Lactarius scrobiculatus inedible. It is collected and eaten in parts of eastern Europe and Russia after salting, pickling and thorough cooking. Consuming it irritates the gastrointestinal tract, causing symptoms of gastrointestinal syndrome.
Careful preparation seeks to neutralise the acrid taste. This usually involves a process of boiling, during which the water is discarded. Further cooking and pickling may not eliminate the possibility of distressing symptoms.
Lactarius scrobiculatus Toxicity
Although it is unlikely to cause death or long-term illness, this is a poisonous mushroom and should not be gathered for eating because it can cause unpleasant stomach pains, sickness, and a burning sensation in the throat. It almost goes without saying that in some parts of Europe these fungi are eaten after frequent boiling and discarding the water to reduce the level of toxins.
Lactarius scrobiculatus Taxonomy and Etymology
This milkcap was first validly described in 1772 by Italian mycologist Giovanni Antonio Scopoli, who gave it the binomial scientific name Agaricus scrobiculatus.
It was the great Swedish mycologist Elias Magnus Fries who, in 1838, transferred this species to the genus Lactarius, thereby establishing its currently-accepted scientific name of Lactarius scrobiculatus.
Synonyms of Lactarius scrobiculatus include Agaricus scrobiculatus Scop., and Agaricus intermedius Fr.
The generic name Lactarius means producing milk (lactating) - a reference to the milky latex that is exuded from the gills of milkcap fungi when they are cut or torn. The specific epithet scrobiculatus comes from Latin scrobis, meaning a trench. The diminutive form scrobiculus is a small trench or pit (a planting hole, for example), and scrobicules is the technical name for those oval pits on the stem surface of a subgroup of Lactarius known as the 'Scrobiculati'.
Photo 1 - Author: Jerzy Opioła (Creative Commons Attribution-Share Alike 4.0 International)
Photo 2 - Author: Holger Krisp (Creative Commons Attribution 3.0 Unported)
Photo 3 - Author: Irene Andersson (irenea) (Creative Commons Attribution-Share Alike 3.0 Unported)
Photo 4 - Author: amadej trnkoczy (amadej) (Creative Commons Attribution-Share Alike 3.0 Unported)
Photo 5 - Author: Th. Kuhnigk (Creative Commons Attribution-Share Alike 3.0 Unported)