Grass green russula

Description

The grass-green russula is a russula with a cap 3–10 cm across, in shades of green, olive to yellow-green, usually darker in the centre, with a smooth cuticle that can be peeled from almost the whole cap. The gills are crowded, white to cream, the stem white, solid, with rusty spots at the base.

It grows from June to November in deciduous, coniferous and mixed forests and in parks, most often under birches. In Poland it is one of the most commonly encountered russulas. The gills may burn slightly, and after cooking the bitter taste fades.

Warning: because of the green cap it can be confused with the deadly poisonous death cap. Always dig up the whole base of the stem: the death cap has a ring, a bulb and a sac-like volva, and the russula has none of them. If you are not sure, do not collect or eat it.

Identification features

Cap

Diameter 3–10 cm; globose when young, then broadly spread out, concave in the centre, according to some descriptions funnel-shaped. Surface smooth, dry, matt (according to some descriptions slightly sticky and shiny), notched or faintly striate at the margin, slippery in rain. Colour from green through olive-green to yellow-green or grey-green, usually darker in the centre. The cuticle can be peeled from almost the whole cap.

Hymenophore (underside of the cap)

Gills wide, crowded, of different lengths, not attached or only slightly attached at the stem; white or pale cream when young, cream to light yellow in older ones.

Stem

Smooth, cylindrical (according to some descriptions often with longitudinal grooves), white, with rusty spots at the base, without a ring; height 4–8 cm, thickness 1–2 cm. Solid in young specimens, spongy inside in older ones. No bulb or volva.

Flesh

Hard, white and brittle. Taste is described as slightly burning, especially the gills, or mild; smell indistinct. With FeSO4 greyish-pink. Do not taste the flesh of unknown mushrooms.

Spore print and spores

Spore print light cream or creamy yellow. Spores ellipsoid or obovate, covered with fine warts up to 0.6 µm, blunt, partly joined by thin connections. Size: 7–10 × 6–7 µm or 6–8 × 6–7 µm (descriptions give different ranges).

Habitat and distribution

Ecology. Terrestrial mycorrhizal fungus, mainly with silver and downy birch, less often with sycamore, beech, spruce, pine and black locust. Grows in deciduous, coniferous and mixed forests, also in parks, on litter or grass, often in groups.

Distribution. Temperate zone of the Northern Hemisphere: Europe, North America, according to some descriptions also East Africa. In Poland one of the most common russulas. Not legally protected in Poland.

Fruiting. From June (according to some descriptions from July) to November.

What can it be confused with?

• Amanita phalloides (the death cap) — DEADLY POISONOUS — Has a ring on the stem, a bulbous base with a sac-like volva, white gills and a white spore print; the russula has no ring or volva, and its flesh is brittle. The volva may be hidden in the litter, so the base of the stem must be dug up.
• Amanita citrina (the false death cap) — Sometimes confused with the grass-green russula; detailed differences — no data.
• Russula heterophylla (Polish: gołąbek oliwkowozielony) — Taste not burning, cuticle peels only to about 1/3 of the cap radius.
• Russula xerampelina (green forms) — Always smell of cooked crustaceans; the grass-green russula does not.

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

• It is one of the most common russulas in Poland.
• The epithet aeruginea derives from the Latin word for copper patina (verdigris).
• Adult pleasing fungus beetles Tritoma angulata have been recorded on it as an occasional food.
• In Polish literature it appears under two names: formerly "gołąbek grynszpanowy", now "gołąbek białozielonawy".