What You Should Know
Lactarius serifluus is an inedible mushroom that coexists, being a mycorrhizal symbiont (it forms mycorrhizae on the roots of trees). The milk (latex) that exudes from damaged gills is mild tasting and almost colorless; this together with its generally darkish coloring and wrinkled cap surface helps separate this species from the many other small brownish woodland milk caps.
Grows from the plains to the hills, but not in mountainous regions, solitary and smaller groups, on clayey or calcareous soil, through grass, in deciduous forests at their edges, and through parks, always under oak trees.
Other names: Watery Milkcap.
Lactarius serifluus Mushroom Identification
2 to 8cm in diameter, the dark reddish-brown caps have a radially-wrinkled surface; convex at first, the caps flatten and may become slightly depressed with a small umbo as the fruitbody matures.
The clay-buff to clay-pink gills are adnate or weakly decurrent and moderately spaced to crowded. When the gills of this milkcap is damaged, a watery latex is released; it does not change color, and its taste is mild.
Cylindrical, hollow, 3 to 13mm in diameter and 2.5 to 5cm tall, the stems are smooth and pale reddish-brown to orange-brown. There is no stem ring.
Broadly ellipsoidal (almost spherical), 6-8.5 x 5.5-8μm, hyaline; ornamented with warts up to 1.2μm tall joined via a well-developed and almost complete network of ridges.
Pale creamy white.
Odor and Taste
Odour slight, of Fenugreek (or some say of bugs!); taste mild.
Ectomycorrhizal; in broadleaf and mixed woodland, usually under oaks but occasionally under birches.
August to November.
Lactarius serifluus Taxonomy and Etymology
The Watery Milkcap was described in 1815 by Swiss botanist Augustin Pyramus de Candolle, who gave it the scientific name Agaricus serifluus. (Vast numbers of gilled fungi were dumped into the Agaricus genus in the early days of fungal taxonomy; most have since been moved to other genera leaving in the present-day Agaricus genus a much smaller number of gilled mushrooms that are sometimes referred to as the 'true mushrooms'.) Swedish mycologist Elias Magnus Fries sanctioned the basionym in 1838, establishing this milkcap's currently accepted scientific name as Lactarius serifluus.
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 serifluus is derived from the Latin noun serum, meaning whey (the watery part of curdled milk), and the Latin verb fluo, meaning 'I flow'. It is a reference to the watery latex (milk) that flows from the damaged gills of this milkcap mushroom.
Lactarius serifluus Synonyms
Agaricus serifluus DC.
Lactarius subdulcis var. cimicarius sensu Gray
Galorrheus serifluus (DC.) P. Kumm.
Lactarius cremor ssp. Dahncke, Marchand Neuhoff
Lactarius noncamphoratus Bassler & Schaeff.
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