Slimy Spike

Description

The slimy spike is a medium-sized mushroom with a cap 4–15 cm across, covered with slime, violet-grey when young, then brown, finally ochre. It has widely spaced, decurrent gills, whitish and then grey, and a white, slippery stem with a yellow base and a fugacious ring. The cap margin is inrolled, and slimy remnants of the veil often hang from it.

It grows in coniferous forests, almost exclusively under spruces, on acidic soils, often among bilberries, from July to November. In Poland it is rare and is on the Red List of Plants and Fungi (status R), so it is not worth collecting in large numbers.

Brownish specimens can be confused with slippery jacks, but the slimy spike has gills, not tubes. Similar too are the spikes of the genus Chroogomphus (not slimy, with a reddish-brown or orange-brown cap) and the larch spike (under larches).

Identification features

Cap

Diameter 3–15 cm (descriptions give different ranges); young bluntly conical, then hemispherical, arched, finally flat, depressed in the centre or even funnel-shaped; margin always inrolled. Surface smooth, covered with slime (drying in dry weather). Young fruiting bodies violet-grey or grey-brown, older ones chocolate-brown, finally ochre; blackish spots may appear. Slimy remnants of the veil often hang from the margin.

Hymenophore (underside of the cap)

Gills widely spaced, of different lengths, often forked, waxy, decurrent; whitish when young, then grey, darkening from the spores.

Stem

Height 2–10 cm, thickness 0.7–3 cm (descriptions give different ranges), cylindrical, solid, slippery, narrowing towards the base. Ring fugacious, left from the slimy veil. Surface whitish, yellow in places below; the yellow part stains dark green to black with Melzer's reagent.

Flesh

Whitish, brownish under the cap, lemon-yellow in places in the lower part of the stem; may have a wine-coloured tinge. Mild taste, weak smell.

Spore print and spores

Spore print black or brownish-black. Spores elongated, spindle-shaped, smooth, 17–22 × 5–8 µm (descriptions give different ranges).

Habitat and distribution

Ecology. A terrestrial fungus traditionally regarded as mycorrhizal, almost exclusively under spruce, very rarely under other trees (hornbeam, linden); according to more recent research many species of Gomphidiaceae parasitise mycorrhizal boletes (e.g. slippery jacks of the genus Suillus). Prefers acidic and not very moist soils, especially in the presence of bilberries. A hyperaccumulator of caesium and heavy metals.

Distribution. The whole Northern Hemisphere in the temperate zone (Eurasia and North America). Rare in Poland; on the Red List of Plants and Fungi of Poland (2006) it has the status R (rare, potentially threatened because of its limited range and small habitat areas). It is not under species legal protection in Poland (list of Dz.U. 2014 item 1408).

Fruiting. From July to November; in Europe in autumn, even up to December.

What can it be confused with?

• Gomphidius maculatus (larch spike) — Grows under larches; cap flesh-ochre to brown-flesh, covered with dark brown spots.
• Chroogomphus helveticus (Alpine spike) — Not slimy; fruiting body orange-brown to pink-violet.
• Chroogomphus rutilus (copper spike) — Not slimy; cap reddish-brown.
• Suillus luteus (slippery jack) — Brownish specimens can be confused from a distance, but the slippery jack has tubes and pores under the cap, while the slimy spike has gills.
• Hygrophorus hypothejus (herald of winter) — Grows in a similar habitat, but has yellow gills that do not separate from the cap.

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 genus name comes from the Greek “gomphos” (a peg, a large wedge), and the epithet “glutinosus” from the Latin for “sticky”.
• Despite its gills it belongs to the order Boletales, together with the boletes.
• According to more recent research, the species may parasitise mycorrhizal fungi of the genus Suillus rather than being a typical mycorrhizal symbiont.
• It is a caesium hyperaccumulator, concentrating it more than 10,000-fold relative to the background.