Common Yellow Russula

Description

The common yellow russula has a cap 4–8 cm across, dull yellow, from yellowish ochre to lemon, sticky in wet weather. The gills are brittle, white, turning cream with age and developing ochre patches. The stem is white, often with an ochre tint, firm, and the flesh is white, greying near the stem.

It grows from summer to autumn in coniferous and mixed forests, most often under spruce. In Poland it is very common and can be the only mushroom found in quantity, even in dry summers.

It is hard to tell apart from similar yellow russulas without checking the taste and the tree it grows under: Russula claroflava grows under birch, Russula solaris grows under beech and has a burning taste, and Russula fellea smells of geranium and tastes acrid. If you are not sure of the species, do not pick or eat it.

Identification features

Cap

Diameter 4–8 (10–12) cm; hemispherical when young, later flat, wavy and slightly bent over, sometimes slightly depressed. Cuticle smooth, sticky in wet weather and dry in dry weather, peelable to about half the radius of the cap. Colour yellowish ochre to lemon, dull yellow. Margin blunt, slightly turned under, furrowed and bumpy in older fruiting bodies.

Hymenophore (underside of the cap)

Gills brittle, moderately crowded in young fruiting bodies and more distant later; sinuate or almost free at the stem (according to some descriptions also weakly attached), rounded at the margin, sometimes forked. White at first, then pale cream to greyish white, in places with ochre patches.

Stem

Height 3–7 cm, thickness 1–2 cm, cylindrical, firm, solid at first, later cottony (pithy). Surface smooth, slightly shiny, white, often with a pale ochre tint, and may have ochre patches; greys with age. No ring.

Flesh

White or whitish, greying near the stipe, fairly soft. Odour very faint. Taste mild, in most specimens tolerably acrid, and sometimes bitter or burning (especially the gills). Do not taste the flesh for identification if you are not sure of the species.

Spore print and spores

Spore print white to pale cream. Spores 8–10.5 × 7–8 µm, warty-reticulate; warts large, conical, mesh of the reticulum narrow, in places open; suprahilar spot distinct, amyloid.

Habitat and distribution

Ecology. Terrestrial mycorrhizal fungus. Most often grows under spruce, less often under pine and beech, even less often under other trees; in coniferous, mixed and deciduous forests.

Distribution. Widespread in Europe, also found in North America (under conifers, birch and aspen in the northern states of the USA) and in Japan. Very common in Central Europe, in places abundant; it also grows during droughts. Common in Poland, the most frequently encountered of the yellow russulas. Not legally protected in Poland.

Fruiting. From summer to autumn.

What can it be confused with?

• Russula fellea (geranium brittlegill) — Honey-yellow colour, smell of geranium, burning taste; inedible. The cap margin has a colour little different from the gills, whereas in the common yellow russula the difference is distinct.
• Russula claroflava (yellow swamp russula) — Grows only under birch; none of its specimens have an acrid taste.
• Russula solaris (sun russula) — Burning taste; grows only under beech.

Never rely on a single feature. If you are not sure — do not pick it; show the mushroom to a qualified mushroom expert.

Interesting facts

• Variability of taste, from mild to burning, is a rare trait among russulas.
• It is often the only mushroom found in quantity during droughts.
• The first description dates from 1801, when Persoon described it as Agaricus ochroleucus; the current name was given by Fries in 1838.
• The Polish name was given by Feliks Berdau in 1876.