Birch Milkcap

Lactarius tabidus Fr.

3 Observations

7 days ago Last Observed

The Birch Milkcap (Lactarius tabidus) is a small, orange-brown milkcap found almost anywhere birch grows. Its cap has a small central bump and a finely wrinkled surface, and when the gills are damaged they release white milk. A simple test is to dab the milk onto a white tissue or handkerchief and within seconds it turns yellow. The milk tastes mild at first and then hot.

It grows in damp, mossy birch woodland on acid soils, from summer into autumn, and is one of the commonest milkcaps in Britain. The Mild Milkcap (Lactarius subdulcis) grows with beech and its milk does not turn yellow. It is not poisonous, but its hot milk makes it inedible. It is also known by the older name Lactarius theiogalus.

Spore Print

Season

Native

non-toxic

Distribution

Very common and widespread

Habitat

Occurs on acidic soils with both deciduous and coniferous trees

Etymology

Lactarius is Latin for 'producing milk', after the latex. tabidus is usually glossed as 'stunted', after its small size, though the classical word means 'wasting away'.

Associates

Betula

Conservation

LC - Least Concern

IUCN Red Data List - Lactarius tabidus
Assessment date: 2025

Cap

The cap is 2-5 cm across, convex to umbonate, becoming depressed or expanded. It is hygrophanous, yellowish-brown to pinkish-buff, and radially wrinkled around the umbo, with a crenate margin.

Colour
Shape	Convex, Umbonate, Depressed, Expanded
Surface	Hygrophanous
Width	2 - 5 cm
Margin	Crenate

Gills

The gills are pinkish-buff, close and adnate to decurrent, becoming blotchy with age. The white milk is fairly abundant, turning pale yellow on white tissue.

Colour
Attachment	Adnate, Decurrent
Spacing	close

Flesh

The flesh is soft, brittle and pinkish-buff, and often hollow in the stem. It has a faint smell of bedbugs, and the taste is mild at first, then bitter and acrid.

Colour
Odour	Faint bedbugs!
Taste	Mild then bitter acrid

Stem

Brittle and often hollow; paler at the top and darker towards the base.

Colour
Height	3.5 - 7 cm
Width	5 - 10 mm
Texture	Smooth
Shape	Clavate, Cylindric

Spores

The spores are subglobose to ellipsoid, amyloid, 6-8.6 x 5-7 μm, with isolated warts and ridges forming irregular crests up to 1.2μm high and a partial reticulum.