Slimy spike

Overview

The slimy spike, Gomphidius glutinosus, is a gilled mushroom of the order Boletales, the group that includes the boletes. Its whole young fruit body is covered in a slimy veil, and the cap stays sticky. It grows under conifers in woods and plantations, and it occurs up to 2,900 metres.

The species is recorded as a cooked woodland mushroom in northern Europe. The sources describe it as edible, but they do not recommend it as a regular food, and they note that it accumulates heavy metals.

Taxonomy and names

Jacob Christian Schaffer described the species as Agaricus glutinosus in 1774. Elias Magnus Fries placed it in Gomphidius in 1838, giving the authority (Schaeff.) Fr. Synonyms include Agaricus mucosus and Cortinaria viscida. Orson Miller described two varieties in 1971, purpureus and salmoneus. The catalogue records the scientific name as a research label rather than a reconciled accepted name, so records should be checked against current taxonomy.

Description

The cap is 3 to 12 cm across, dull dark purple, brownish or grey, smooth, sticky, with a central boss and an inrolled margin. The stipe is white, 4 to 10 cm tall, with a yellow base that stains dark green to black with Melzer's reagent. The gills are widely spaced, decurrent, waxy, whitish when young and grey as they darken with spores. The spore print is brownish-black, and the spores are spindle-shaped, 17 to 20 by 5.5 to 6 micrometres.

Habitat, ecology and season

The species grows under conifers such as balsam fir, Norway spruce and grand fir, in natural woods and plantations, singly, scattered or in clusters. It occurs up to 2,900 metres and fruits in autumn, sometimes as late as December in northern California.

Gomphidius species were once thought to be ectomycorrhizal. Wikipedia now says that many, possibly all, species of the family are parasitic on ectomycorrhizal boletes. For this species the sources say it is possibly a parasite on Suillus and Rhizopogon mycelium, and it has been found under pines where Suillus grevillei was present.

Look-alikes

Brownish specimens can resemble Suillus luteus, but Gomphidius has gills where Suillus has pores. Hygrophorus hypothejus has yellow gills that do not separate from the cap. G. smithii of North America has a paler purple to wine-coloured cap, and G. oregonensis and G. subroseus are also similar. The sources do not treat Gomphidius roseus or Chroogomphus rutilus as dangerous.

Preparation and quality

The Wikipedia article describes the flavour as mild and suited to mixed dishes, soups and stews, and it says the species is not suited to drying. It advises removing the slime and the skin of the cap as soon as possible after picking. Opinions on its table quality differ: some guides hold it in high regard, while others view it with caution.

The sources reviewed do not give a cooking time or a method beyond the slime and skin removal advice.

Safety

The Wikipedia infobox rates the slimy spike as edible but not recommended. The article records that the species accumulates heavy metals, and it contains no explicit toxicity statement. No safe quantity is given.

Appearance, smell and taste do not establish that a mushroom is safe to eat. Confirm the identification by checking gills against pores with an experienced local expert, and follow official food safety advice before eating any wild mushroom.

Open questions

The sources do not give a regional cooking tradition, a dated food history, a local name, or the level of heavy metals in a typical specimen. These are unknown, not negative findings.