Laughing Jim

Description

The spectacular rustgill is a large, yellow-orange to rusty-brown mushroom with a dry cap covered with brown scales, usually 6–15 cm across (sometimes much larger). It has attached gills, yellowish, then rusty-brown, and a long, yellow stem with a persistent ring. The flesh is yellow, with a pleasant smell, but bitter in taste.

It grows from July to October in clusters on trunks, stumps and rotting wood, especially of birch, pine and oak. In Poland it is rare.

Older and smaller specimens can be confused with the shaggy scalycap or honey fungi. If you are not certain of the species, do not collect or eat it.

Identification features

Cap

Diameter 5–30 cm (some descriptions give 6–15 cm). Bun-shaped and suede-like when young, then convex, finally spread out. Colour yellow-ochre, yellow-rusty, reddish, brown-orange (bright yellow-orange in young ones, orange-brown to red-brown in older ones). Surface dry, covered with embedded brown scales.

Hymenophore (underside of the cap)

Gills moderately crowded, attached or slightly decurrent with a tooth; at first cream, then pale yellow-brown, finally rusty-brown.

Stem

Height 8–20 cm (5–25 cm according to some descriptions), thickness 1–3 cm (up to 5 cm according to some descriptions), cylindrical to spindle-shaped, thickened below and often rooting. Ring fairly persistent (frail, dusted with rusty-orange spores according to some descriptions). Above the ring smooth, dusted; below the ring covered with fine brown fibrils and shaggy hairs. Colour pale yellow, darkening to red-brown towards the base.

Flesh

Firm, yellow. Smell pleasant, mushroomy (mild according to some descriptions); taste bitter — it must not be tasted; do not taste the flesh of this or any suspicious mushroom. Turns red with KOH and green after cooking; does not turn blue (although smaller specimens sometimes discolour slightly).

Spore print and spores

Spore print rusty-brown. Spores rusty-orange, ellipsoid, rough, 7–15 × 4.6–6 µm.

Habitat and distribution

Ecology. Saprotroph growing in clusters (from a few to several dozen fruiting bodies), less often singly, on trunks, stumps, rotting wood and at the base of trees, especially birch, pine and oak (deciduous and coniferous wood); most frequent in damp lowland areas near rivers.

Distribution. Widespread in Europe; also Japan, Australia, New Zealand, South America. Its occurrence in North America is disputed: some descriptions give it, others claim the species does not occur there and that similar mushrooms are misidentified. In Central Europe it occurs sparsely, in Poland it is rare. Not legally protected in Poland.

Fruiting. From July to October.

What can it be confused with?

• Pholiota squarrosa (shaggy scalycap) — Older and small specimens of the rustgill may be confused with it; the rustgill is distinguished by its larger size, colour and the ring on the stem. Detailed differences: no data.
• Armillaria mellea (honey fungus) — Sometimes confused; detailed differences: no data.
• Omphalotus olivascens — A similar, poisonous, bioluminescent species from North America; detailed differences: no data.
• Gymnopilus ventricosus, G. luteus, G. subspectabilis — Sometimes confused; G. luteus and G. subspectabilis contain psilocybin, G. ventricosus does not. Detailed differences: no data.

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 larger mushrooms growing on wood: the cap can be as much as 30 cm across.
• Unlike some related rustgills it does not contain psilocybin and does not turn blue.
• After cooking the flesh turns green, and in a KOH solution it turns red.
• It contains hispidin and bis-noryangonin, compounds structurally related to the alpha-pyrones found in kava.