Agaricus sylvaticus

Description

Agaricus sylvaticus (or Agaricus silvaticus) is a species of mushroom often found in groups in coniferous forests from early summer, or September through to November in Europe, North Africa and North America. The grayish-brown cap is hemispherical when young but later flattens out up to 10 cm in diameter. It is covered with broad scales. The gills are grey when young, and become much darker with age. The spores are chocolate brown. The stem is brownish, often with a hanging ring and a small bulb at the base. The flesh is white with a mild taste, turning reddish when cut.

Although one field guide lists the species as edible, another does not recommend it based on its being related to species that cause gastric upset.

Agaricus sylvaticus is sometimes referred to as the Red Staining Mushroom because the cap and stipe turn bright red if they are scratched or broken.

Common names: Red Staining Mushroom, Blushing Wood Mushroom, Scaly Wood Mushroom, Blushing Wood Mushroom, Pinew, Skogschampinjon (Sweden), Meža atmatene (Latvia).

Mushroom Identification

1. Cap

   7 to 15 cm in diameter. Domed at first, the scaly cap expands until it is almost flat. The flesh is white below the surface, light reddish-brown, and covered with reddish-brown scales that are denser the closer to the center of the cap. When cut, the thin, firm cap flesh turns red and eventually brown.

2. Gills

   Initially pink, the free, crowded gills become redder, then dark brown as the spores mature.

3. Stem

   1 to 1.2 cm in diameter, more or less parallel to the slightly swollen or bulbous base. When cut or bruised, the tough stalk flesh turns red and eventually brown. Above the large, loose single ring, the stem is smooth, while below the ring are thin scales.

4. Spores

   Ovoid, 4.5-6.5 x 3.2-4.2µm.

5. Spore Print

   Chocolate brown.

6. Odor and Taste

   Not distinctive.

7. Habitat & Ecological Role

   Often grow in groups in mixed woodland and under trees in parks.

Look-Alikes

1. Agaricus haemorrhoidarius

   Normally considered a synonym, but has also been defined as a separate species, distinguished by its flesh which immediately turns red when cut.

2. Agaricus phaeolepidotus

   Distinguished by a stem that yellows (in addition to turning pink) when cut. The cap background is browner than A. silvaticus and its smell suggests iodine or ink.

3. Tricholoma vaccinum

   Looks similar from above but has no ring and develops reddish-brown gills.

History

The species name sylvaticus (or silvaticus) means "of the woods". Both spellings are found in the literature, but Species Fungorum gives sylvaticus as the current name and so that version should be preferred.

This well-known species was first validly described under the current name, Agaricus silvaticus, in 1774 by the early mycologist Jacob Christian Schäffer. At that time most gilled mushrooms were all grouped under the genus Agaricus, but later were allocated to new genera which reflected their different characteristics.

Now Agaricus has a much more restricted meaning, being the genus of the commonly cultivated mushrooms of Europe and America, but A. sylvaticus belongs to that group and has kept the same name during all that time.

Synonyms

1. Agaricus haemorrhoidarius

2. Agaricus sanguinarius

3. Agaricus vinosobrunneus

4. Fungus amethystinus

5. Fungus haemorrhoidarius

6. Fungus sanguinarius

7. Fungus sylvaticus

8. Pratella amethystina

9. Pratella haemorrhoidaria

10. Pratella sylvatica

11. Psalliota amethystina

12. Psalliota haemorrhoidaria

13. Psalliota sanguinaria

14. Psalliota sylvatica

Photo sources:

Photo 1 - Author: Holger Krisp (CC BY 3.0)

Photo 2 - Author: Jerzy Opioła (CC BY-SA 3.0)

Photo 3 - Author: Jerzy Opioła (CC BY-SA 3.0)