Lactarius blennius
Description
Lactarius blennius is a medium-sized mushroom of the genus Lactarius found commonly in beech forests in Europe, where it is mycorrhizal, favoring the European beech (through associations with other trees are known). Its color and size vary, it is distinctive because it is slimy when wet and exudes copious amounts of milk.
Common names: Slimy Milk-cap, Beech Milkcap.
Mushroom Identification
Cap
Drab greenish-gray or olive-gray, sometimes with a pinkish tinge as see on the left, with rings of darker watery depressed blotches, the caps of Lactarius blennius are convex, developing a slight central depression; 4 to 9cm across.
The slimy nature of the caps during wet weather is less evident in the specimen shown on the left, which was photographed during a dry spell.
Gills
White, gradually becoming cream, turning gray-buff when cut, the gills of the Beech Milkcap are adnate or slightly decurrent; crowded.
When damaged the gills release abundant white latex that dries grey.
Stem
Pale grey, cylindrical or tapering slightly towards base, stems of the Beech Milkcap are 3 to 7 cm long, 0.9 to 2cm in diameter.
Spores
Broadly ellipsoidal, 6.5-8 x 5.5-7µm; ornamented with low warts joined by ridges and with a small number of cross-connections.
Spore print
Cream.
Odor and Taste
No significant odor; taste bitter and hot.
Habitat & Ecological Role
Nearly always under beech trees, with which it is mycorrhizal, Lactarius blennius is very occasionally found also with oaks.
Similar Species
Lactarius turpis, the Ugly Milkcap, is darker and develops sepia tinged areas on its gills.
History
The Beech Milkcap was described in 1815 by the great Swedish mycologist Elias Magnus Fries, who gave it the binomial scientific name Agaricus blennius.
It was also Fries who, in 1838, transferred this woodland mushroom species to its present genus, thereby establishing its name as Lactarius blennius, which is still its generally-accepted scientific name today.
Synonyms of Lactarius blennius include Galorrheus blennius (Fr.) Fr., Lactifluus blennius (Fr.) Kuntze, Agaricus viridis Schrad., and Lactarius viridis (Schrad.) Quel.
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 blennius comes from the Latin blennius, which means slimy.
Uses
Mycologist Roger Phillips claims that L. blennius is edible when cooked, but not recommended, while others describe it as inedible or even poisonous. The milk tastes very hot and acrid.
Lactarius blennius has been the subject of some chemistry research. Lactarane derivatives (known as "blennins") have been acquired from the mushroom, including the lactone blennin D, and blennin A, which was first isolated from this species. Lactaranes are chemicals so named because of their occurrence in Lactarius species. Blennins are potentially useful- blennin A, for instance (a lactarane-type sesquiterpene) is an anti-inflammatory, having a strong inhibitive effect against leukotriene C4 biosynthesis. L. blennius can also be refined to create a green pigment, known as blennione.
Photo sources:
Photo 1 - Author: Strobilomyces (CC BY-SA 3.0)
Photo 2 - Author: James Lindsey (CC BY-SA 2.5)
Photo 3 - Author: Strobilomyces (CC BY-SA 3.0)
Photo 4 - Author: Thomas Pruß (CC BY-SA 3.0)