Ruby bolete, the most colorful of the Xerocomus group

If a bright red mushroom cap flashes at you from the moss or grass, chances are it's the ruby bolete (Boletus rubellus), which field guides also call the many-colored bolete. It's the most colorful of our Xerocomus boletes.

It's small and delicate, but it fully deserves its share of attention: it's hard to mistake for anything else. Let's look at how to recognize it, where to find it, and whether it belongs in your basket.

How to recognize it

The ruby bolete's main feature is right there in its name: its vivid color.

• Cap red, carmine, cherry or pinkish brown, dry and velvety, cracking slightly with age.
• Tubes yellow or greenish yellow, with large pores.
• Stem slender, often with a distinct red or pink tint toward the base.
• Flesh yellowish, turning blue when cut, especially at the base of the stem.

It's the bright red cap combined with yellow pores and blue-staining flesh that makes this mushroom so recognizable. Among its modest gray-brown relatives, it looks like a guest dressed for a party.

Why it turns blue when cut

Like most Xerocomus boletes, the ruby bolete turns blue when cut, and that's perfectly normal.

When you cut the mushroom, the flesh quickly takes on a bluish tint in the air, especially at the base of the stem. This is an ordinary oxidation reaction, not a sign of poison.

Near the base of the stem, this species often shows tiny reddish dots in the flesh, another telltale feature. The blue color disappears during cooking.

Where and when to look for it

The ruby bolete loves bright, warmer spots, most often in deciduous forests.

• in deciduous forests, along forest edges and in clearings, often under oak;
• in mixed forests, where broadleaf trees grow alongside conifers;
• on grassy roadsides, in parks and old plantations.

Its season is long, from June through October. It's a warmth-loving mushroom, so it fruits more actively in warm weather after rain.

Is it worth picking

The ruby bolete is edible, but it has a quirk: it's small, thin-fleshed and fragile. You won't get a big harvest out of it.

Its flesh is soft and watery, so the mushroom ages fast and turns mushy. Pick it while very young and cook it right away, together with other mushrooms.

It's poorly suited to pickling and drying, but works just fine fried or in soup. You can easily tell it from the suede and red cracking boletes by its bright cap, but all of them are edible.

The only unpleasant lookalike among these boletes is the fiery peppery bolete with reddish pores. To know exactly when to head out for Xerocomus boletes, check our mushroom radar: it shows when moisture and warmth line up just right for mushrooms to appear.

Sources

• “Identification Guide to the Fungi of Ukraine” (Kyiv, Naukova Dumka publishers).
• Hortiboletus rubellus on GBIF, the global biodiversity database.
• Hortiboletus on MycoBank, the international fungal nomenclature database.
• Hortiboletus rubellus on Wikipedia.