Cat's Tongue

Description

The cat's tongue is a small, gelatinous fungus with a tongue-shaped or bracket-shaped cap, usually 2–7 cm wide. The top is whitish, pale grey or tan, granular or warty, and the flesh is glassy and slightly translucent. The underside is covered with dense, whitish spines up to 3 mm long, which distinguishes it from other gelatinous fungi. The stem is short and attached at the side, or absent.

It grows in coniferous and mixed forests on dead wood, most often spruce and pine, usually in clusters whose fruiting bodies overlap like roof tiles. It is easiest to find from summer to autumn, although it sometimes appears in spring and winter too. In Poland it is common.

What matters most in identifying the species is the spined underside combined with the gelatinous consistency. If you are not sure of the species, do not pick it and do not eat it.

Identification features

Cap

Fruiting body tremelloid, gelatinous and very watery; when dried it shrinks to a thin flake. Cap spatulate, tongue-shaped or bracket-shaped, 1–8 cm wide (usually 2–7 cm). Upper surface granular or warty. Colour whitish with a bluish tinge, ranging from white through pale grey to tan-yellow; grey or pinkish-brown specimens on the upper side of the cap also occur.

Hymenophore (underside of the cap)

Spined: dense, conical spines up to 3 mm long, the colour of the fruiting body (whitish to pale grey). The hymenophore covers the underside of the cap.

Stem

Short, eccentrically attached or lateral; the fruiting body may also be attached sideways to the wood and lack a stipe. In western North American forms the stipe is often more distinct and upright. No ring.

Flesh

Whitish with a pale bluish tinge, gelatinous, watery, slightly translucent (glassy). No distinct taste or smell. Do not taste the flesh for identification.

Spore print and spores

Spore print white (colourless to white). Spores nearly spherical, smooth, 3.5–6.5 × 5–8.5 µm.

Habitat and distribution

Ecology. Wood-dwelling saprotroph growing on dead conifer wood, usually spruce and pine. Found in coniferous and mixed forests, usually in groups of several fruiting bodies growing in overlapping tiers.

Distribution. Formerly considered cosmopolitan; recent DNA studies suggest that the species in the strict sense occurs in Europe and northern Asia, while similar but distinct taxa grow on other continents. Common in Poland. Not legally protected in Poland.

Fruiting. In Poland most often from summer to autumn; occasionally also in spring and winter, and according to some descriptions fruiting bodies can be found all year round.

What can it be confused with?

• Hyalodon piceicola (spruce jelly-spine fungus) — Fruiting body spread flat, without a distinct cap; in Poland reported only from the Białowieża Forest.
• Other white and gelatinous fungi occurring in Poland — They lack a spined hymenophore, so if you check the underside of the fruiting body they should not be confused with the cat's tongue.

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

• The scientific and English names (toothed jelly fungus, cat's tongue, jelly tooth) refer to the gelatinous consistency and the spined underside of the fruiting body.
• Described in 1772 by Giovanni Scopoli as Hydnum gelatinosum; moved to its current genus in 1868 by Petter Adolf Karsten.
• The fruiting body contains so much water that when dried it shrinks to a thin flake.
• Recent DNA studies suggest that the species in the strict sense occurs only in Europe and northern Asia, while similar fungi from other continents belong to distinct taxa.