Grey larch bolete, the slimy grey mushroom under larches

Larch is home not only to the bright yellow slippery jack but also to its much humbler neighbor, the sticky bolete (Suillus viscidus, listed in our catalog as sticky bolete). It's easy to overlook: the grayish-brown cap blends in among the fallen needles, but the very slimy surface gives it away as a true slippery jack.

This species is valued less than its relatives because of its watery flesh and bland flavor, but it's perfectly edible. Most importantly, it's worth knowing so you don't confuse it with the bright larch bolete that grows nearby.

Another larch slippery jack

Like the larch bolete, the sticky bolete lives in partnership with larch. This bond is called mycorrhiza: the mycelium wraps around the tree's rootlets and trades nutrients with it. So look for it wherever larch grows.

It differs from its bright relative mainly in color: instead of a sunny yellow cap, it has a gray, grayish-brown or dirty olive one, sometimes with a faint greenish tint. The surface is very slimy, especially in wet weather.

Because of its watery flesh and dull flavor, it's often left in the forest. But for those who gather slippery jacks in bulk, it's perfectly usable, especially when young.

How to recognize the sticky bolete

It's identified by a combination of features, not just one. Look the mushroom over from top to bottom.

• Cap. Gray, grayish-brown or dirty olive, very slimy and glossy. The color is dull, with no bright tones.
• Ring. The stem has a membranous ring, like the larch bolete's.
• Pores. The tube layer underneath: grayish or dirty white, darkening with age.
• Flesh. Pale, watery; it may turn slightly blue or green when cut.

The main clue is always twofold: a gray, very slimy cap plus larch nearby. It's that pale, unattractive tone that sets it apart among slippery jacks.

How it differs from the larch bolete

The sticky bolete and the larch bolete grow under the same tree, so it's useful to tell them apart.

1. Color. The sticky bolete has a gray or dirty olive cap; the larch bolete's is bright yellow or orange.
2. Pores. In the sticky bolete they're grayish; in the larch bolete, distinctly yellow.

Both are edible, so a mistake here is harmless. But the larch bolete tastes better, so it's nice to know the difference.

Where and when to look for it

The best spots are:

• conifer plantations and mixed forests with larch;
• parks, avenues and shelterbelts where larch has been planted;
• sunny edges of conifer forest with some larch mixed in.

The season runs from July to October, in flushes after warm rains. The best time to go is a day or two after rain. You can keep track of these windows with our mushroom radar: it shows when moisture and warmth line up well for mushrooms to appear.

A little caution never hurts

The sticky bolete is safe and has no dangerous lookalikes. The main rule stays the same: only pick mushrooms with a spongy underside, not gills. The very slimy skin is usually peeled off. And as always: if you're not sure, don't pick it.

Sources

• “Identification Guide to the Fungi of Ukraine” (Kyiv, Naukova Dumka publishing house).
• Suillus viscidus on GBIF, a global biodiversity database.
• Suillus viscidus on MycoBank, an international fungal nomenclature database.
• Suillus viscidus on Wikipedia.