Cap color

Red

Red in nature is almost always a warning: "Don't touch me, I'm poisonous." In the world of macrofungi this rule works flawlessly, although, as always in mycology, there are exceptions. A bright red, crimson or blood-red cap is a color you can see from dozens of meters away.

24 species in the database.

The symbol of poison

The most famous mushroom in the world, the one drawn in every children's book, has exactly this kind of cap:

Fly agaric (Amanita muscaria).

Its cap is bright red or orange-red thanks to specific pigments (muscarufin). Its surface is scattered with white spots — remnants of the universal veil. This mushroom contains neurotoxins (ibotenic acid and muscimol) that cause severe poisoning and hallucinations. Interestingly, the red pigment itself is water-soluble, and after a few days of heavy rain a fly agaric can "wash out" and turn pale yellow.

Another dangerous "red" species is the sickener (Russula emetica). Unlike the fly agaric, it has neither white spots on the cap nor a ring on the stem. Its cap is a clean, glossy cherry red. The flesh of this mushroom is so burning and acrid that it causes immediate vomiting (hence the name).

Edible mushrooms with red caps

David Arora stresses that not all red mushrooms are poisonous, although picking them takes experience:

1. Bare-toothed russula (Russula vesca): An excellent edible mushroom whose cap is often the color of raw meat or burgundy red. Unlike the sickener, its flesh has a mild, nutty taste (easy to check by licking the cut surface). Besides, the skin on the cap of the bare-toothed russula usually doesn't reach the very edge (leaving the gills exposed).

2. Red-capped scaber stalk (Leccinum aurantiacum): Often has a brick-red or fiery red cap (especially young mushrooms). This is a top-tier edible bolete.

Questions and answers

Why do the white spots sometimes disappear from a fly agaric?

The white scales on the red cap aren't a built-in pattern but remnants of a loose film that protected the mushroom when it was young. A heavy downpour or even rubbing against tall grass can wash these spots off completely, leaving the cap perfectly clean. These "bald" fly agarics are the ones most often confused with red brittlegills.

If a mushroom is red and has a sponge (tubes) underneath, is it edible?

Most boletes with red or brick-colored caps (like the red-capped scaber stalk) are edible. However, if not only the cap is red but the tubes underneath are red too, and the stem has a red net pattern, it may be the poisonous devil's bolete (Rubroboletus satanas) or other dangerous boletes.

Sources

1.Зерова М.Я. та ін. Визначник грибів України. 1979
2.Roger Phillips. Mushrooms (Roger Phillips)
3.David Arora. Mushrooms Demystified
4.Index Fungorum