Pluteus salicinus

What You Should Know

Pluteus salicinus is a wood-rotting fungus that occurs mainly on broadleaf (hardwood) stumps and large logs of buried hardwood timber, particularly of old willow trees. This attractive mushroom can appear at any time from early summer right through to the end of autumn.

Widespread but uncommon in Britain and Ireland, this wood-rotting mushroom is also found in parts of mainland Europe.

Although some sources list this as an edible mushroom, Pluteus salicinus has a form known to contain Psilocybin, a hallucinogenic substance, and so it is inadvisable to gather these mushrooms for eating.

Other names: Knackers Crumpet.

Pluteus salicinus Mushroom Identification

1. Pileus (cap)

   3-7 cm broad, convex to broadly convex, expanding with age to broadly convex to plane. Gray to gray greenish, to blueish gray, darker towards the disc. Surface smooth to finely scaly near the center.

2. Lamellae (Gills)

   Free, not attached. Pallid to cream, soon pinkish to salmon-colored at spore maturity. Stem: 40-100 mm long by 2-6 mm thick. White to grayish-green, often with bluish tones. Flesh often bruising bluish where injured, especially near the base. The base of the stem bruising bluish.

3. Stipe (stem)

   3 - 5(10) long, 0.2 - 0.6 cm thick, more or less equal or slightly swollen at the base, flesh white with grayish-green to bluish-green tones, especially near the base. Ring absent. The firm, full or stuffed.

4. Season

   August through November.

5. Habitat and Distribution

   Growing in the woods mostly on hardwoods in the forests of the pacific northwest, however, reports have been found of this species growing on conifers in an old-growth area.

6. Growth Habit

   Mostly singularly, but sometimes in small groups or two or three in a cluster.

7. Bruising

   The base will show obvious blue bruising, the cap may also have blue spots where handled.

Pluteus salicinus Taxonomy and Etymology

The basionym of this species was established when the Willow Shield was described in 1798 by Christiaan Hendrik Persoon, who gave it the binonial scientific name Agaricus salicinus (at a time when most gilled fungi were placed in the genus Agaricus, since largely redistributed to newer genera).

The Willow Shield was transferred to the genus Pluteus by German mycologist Paul Kummer in 1871, thus establishing its currently-accepted scientific name Pluteus salicinus.

Synonyms of Pluteus salicinus include Pluteus salicinus var. floccosus P. Karst., Agaricus salicinus Pers., and Pluteus salicinus var. beryllus Sacc.

Pluteus, the genus name, comes from Latin and means a protective fence or screen - a shield for example!

The specific epithet salicinus means of or pertaining to willow trees (Salix species.)

Sources:

Photo 1 - Author: zaca (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 2 - Author: Richard Daniel (RichardDaniel) (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 3 - Author: Dan Molter (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 4 - Author: Richard Daniel (RichardDaniel) (Creative Commons Attribution-Share Alike 3.0 Unported)