Lactarius turpis (Weinm.) Fr. - Ugly Milkcap

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Russulales

Although it is a decidedly dull olive-brown mushroom, the Ugly Milkcap is helped just a little by the fact that it is ectomycorrhizal with birch trees in wet woodland, so that when you come across these inconspicuous fungi they may make an effort by glistening when the sun shines. Even so they can be difficult to spot until you ‘get your eye in’, and particularly so during prolonged dry weather, when the caps appearance is very dull.

In some northern European countries there was a tradition of boiling these milkcaps and then using them to spice up other mushroom dishes. Beware, however: there is now worrying evidence that the Ugly Milkcap may be carcinogenic, and so it should be considered as poisonous.

A chemical test can help confirm the identification of thismushroom. Apply potassium hydroxide (KOH) to the surface of the cap and it will instantly turn purple, as the pictures on the left show.

Identification Guide

	Cap Dark olive-brown with a paler margin, the cap of Lactarius turpis is slimy when wet; initially convex, the centre usually becomes slightly depressed and occasionally retains a small umbo. Caps generally range from 7 to 18cm across when fully developed.
	Gills Cream to pale buff, becoming sepia tinged when bruised; decurrent; narrow and crowded. When damaged the gills exude an abundant white latex, which dries olivaceous.
	Stem Colour as cap or lighter; cylindrical, tapering near base; 4 to 7cm long, 1 to 2.5cm dia.; no stem ring.
	Spores Ellipsoidal, 7.5-8.5 x 6-7μm, ornamented with warty ridges forming a moderately well-developed network. Spore print Cream with a slight salmon-pink tinge.
Odour/taste	No significant odour; taste hot and acrid.
Habitat	Mycorrhizal, under birches in wet woodland.
Season	August to November.
Occurrence	Very common in Britain and Ireland, the Ugly Milkcap also occurs in most parts of mainland Europe where birches are to be found.
Similar species	Lactarius blennius, the Beech Milkcap, is lighter and smaller; it does not develop sepia tinged areas on its gills.

Reference Sources

Fascinated by Fungi, Pat O'Reilly, 2011

Dictionary of the Fungi; Paul M. Kirk, Paul F. Cannon, David W. Minter and J. A. Stalpers; CABI, 2008

Taxonomic history and synonym information on these pages is drawn from many sources but in particular from the British Mycological Society's GB Checklist of Fungi and (for basidiomycetes) on Kew's Checklist of the British & Irish Basidiomycota.