The Least Stinking Brittlegill (Russula subfoetens) is a medium to large brittlegill with an ochre to yellowish-brown cap that is sticky when moist and grooved at the edge. The cream gills are often spotted with rusty brown, and the firm, brittle stem becomes hollow and chambered with age.
It is widespread and frequent in the UK, fruiting from July to October on the ground under broadleaved trees, most often birch. The smell is a mix of sour and fruity notes, milder than in its relatives, and the gills taste very acrid.
It is easily confused with the Stinking Brittlegill (Russula foetens), which is generally larger, more strongly scented and regarded by some authors as the same species in a broader sense. Other ochre-capped brittlegills can look similar too. Brittlegills with a hot taste and unpleasant smell cause stomach upset. This species should not be eaten.
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Distribution
Widespread and frequent
Habitat
Associated with broadleaved trees, especially Betula
Etymology
Russula is Latin, from russus meaning red, with a diminutive ending, so "reddish". It was given to the genus because many of its members have red caps, though this species is ochre. The epithet subfoetens combines the Latin prefix sub, meaning almost or somewhat, with foetens, meaning stinking. It marks this as the milder-smelling counterpart of Russula foetens.
Associates
Betula
Conservation
Cap
The cap starts rounded or egg-shaped, then opens out and flattens. The surface is slimy when wet and often uneven or slightly wrinkled. The edge is deeply furrowed, and about half the skin can be peeled back from the margin.
| Colour | |
|---|---|
| Width | 5 - 14 cm |
| Peeling | 1/2 |
Gills
The gills are thick-fleshed and slightly elastic. They are often spotted with rust-brown.
| Colour | |
|---|---|
| Spacing | crowded |
Flesh
The flesh is firm and brittle, but the stem becomes spongy and then hollow in older specimens. When cut or exposed to air, it slowly browns to a reddish-brown. The taste is unpleasant, and very acrid in the gills.
| Odour | Complex mixture of sour and fruity |
|---|---|
| Taste | Very acrid in gills and unpleasant taste |
Stem
The stem is very firm and brittle when young, becoming cavernous (hollow and chambered) with age. The inner flesh turns reddish-brown on exposure to air.
| Colour | |
|---|---|
| Bruising |
Macrochemicals
Guaiac gives a blue reaction. Iron sulphate (FeSO4) turns the flesh a pinkish-buff.
| FeSO4 | |
|---|---|
| Guaiac |
Spores
The spores have warts up to 0.6 µm, which are more or less isolated. Frequent connectives or fused (connate) ridges link some of the warts.
| Colour | |
|---|---|
| Size | 7.2-9.5 x 6-7.2 μm |
Microscopic Features
The pileocystidia (cystidia in the cap skin) are fusiform and appendiculate, meaning they end in a small appendage. They are 5-8 µm across.
Classification
- ↳ Phylum: Basidiomycota
- ↳ Subphylum: Agaricomycotina
- ↳ Class: Agaricomycetes
- ↳ Order: Russulales
- ↳ Family: Russulaceae
- ↳ Genus: Russula
Synonyms
- Russula subfoetens W.G. Smith
- Russula subfoetens var. grata sensu auct.
Reference Sources
T. Læssøe, J. H. Peterson (2019) Fungi of Temperate Europe Vol. 1. Princeton University Press.
G. Kibby, M. Tortelli, F. Hampe, C. V. Soler (2026) The Genus Russula in Great Britain with keys to species. Geoffrey Kibby.
