The Willow Shield (Pluteus salicinus) is a small grey shield mushroom that grows on dead wood, especially willow and alder, in damp broadleaf woodland. Its smooth cap is ash-grey to greyish-brown, often with a blue-green tint, and the free gills turn from white to pink as the spores mature, as in all shields. The stem often shows blue-green staining at the base.
It fruits from late spring well into winter. It is one of the few British wood-growing fungi known to contain psilocybin, which makes it a controlled substance, and it should not be eaten. The Deer Shield (Pluteus cervinus) is larger with a brown cap and no blue tints, and the Velvet Shield (Pluteus umbrosus) has a wrinkled, darker cap.
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Distribution
Widespread and rather common.
Habitat
In broadleaved woodland
Etymology
Pluteus is Latin for a screen or shelter, perhaps after the shield-like cap. salicinus means 'of willow', from the Latin salix, after its favourite host.
Associates
Alnus, Salix
Cap
The cap is 2.5-6 cm across, convex to umbonate and smooth, in ash-grey to greyish-brown shades with a smooth margin. Young caps often show blue-green tints towards the centre.
| Colour | |
|---|---|
| Shape | Convex, Umbonate |
| Surface | Smooth |
| Width | 2.5 - 6 cm |
| Margin | Smooth |
Gills
Free and crowded, white at first and turning pink as the spores mature.
| Colour | |
|---|---|
| Attachment | Free |
| Spacing | Close |
| Edge | Smooth |
Flesh
Thin and pale grey, firm in the cap.
| Colour | |
|---|---|
| Odour | Pelargonium or slightly raphanoid. |
Stem
Pale grey, often with blue-green staining towards the base.
| Colour | |
|---|---|
| Height | 2 - 7 cm |
| Width | 3 - 7 mm |
| Shape | Cylindric |
Spores
| Colour | |
|---|---|
| Shape | Ellipsoid |
| Size | 7-9.5 x 4.5-6.5 μm |
Microscopic Features
| Cheilocystidia | Club-shaped (Clavate) |
|---|---|
| Pleurocystidia | Fusiform |
Classification
- ↳ Phylum: Basidiomycota
- ↳ Subphylum: Agaricomycotina
- ↳ Class: Agaricomycetes
- ↳ Subclass: Agaricomycetidae
- ↳ Order: Agaricales
- ↳ Family: Pluteaceae
- ↳ Genus: Pluteus
Synonyms
- Agaricus salicinus Pers.
- Agaricus salicinus Pers. ex Fr.
- Pluteus petasatus sensu Ricken [Blätterpilze Deutschl.: 277 (1913)]
- Pluteus salicinus (Pers. ex Fr.) P. Kumm.
- Pluteus salicinus var. beryllus (Pers.) P. Karst.
- Pluteus salicinus var. beryllus Pers.
- Pluteus salicinus var. floccosus P. Karst.
Reference Sources
T. Læssøe, J. H. Peterson (2019) Fungi of Temperate Europe Vol. 1. Princeton University Press.
G. Kibby (2020) Mushrooms and Toadstools of Britain & Europe Vol. 2. Geoffrey Kibby.
