AA #6: Mushroom or Toadstool
The cache, a camo-taped preform tube, is hidden just off the path on the edge of the field at a location just above this striking clump of mushrooms . . .
The shaggy scalycap (Pholiota squarrosa) is the 'rather showy' and iconic species of the 150 in this genus of mushroom (or toadstool*) in the family Strophariaceae. Locally common in North America and Europe, it is often an opportunistic parasite, and has a wide range of hosts among deciduous trees, although it can also infect conifers. It is saprobic, deriving nutrients from decomposing wood but may also be mildly parasitic on living but immune-compromised trees. The Latin species name squarrosa comes from squarros meaning 'with upright scales, rough, scurfy, (squarrose) in reference to the prominent scales.
[*This word 1st appeared in C14 England referring to a stool for toad - possibly implying an inedible or poisonous fungus. However, toadstools and mushrooms cannot be scientifically identified or distinguished from one another by shape, colour, or appearance. So, not all toadstools are poisonous and not all mushrooms are safely edible].
It is typically found (as here) growing in cespitose (small, dense) visually striking clusters at the base of trees and stumps. Extensive colonisations which encircle the trunk may indicate compromised structural stability of the tree.
Both the cap and the stem are covered in distinctive small, pointed scales that are pointed downward and backward. These come from a universal veil which tears into scales as the mushroom grows. The crowded gills are yellowish, then later rust-brown.
It has an odour which has been variously described as resembling garlic, lemon, radish, onion, or skunk. It has a strong taste like radishes. Though edible to some, it may be toxic, especially if consumed in combination with alcohol.
It contains unique chemicals which appear to help it infect plants by neutralizing their defensive responses.
Like other Pholiota mushrooms, it has a scaly 3-12cm diameter cap and stem. The cap, depending on its age, may be yellowish-brown to tawny in older specimens, and can range in shape from bell-shaped to rounded to somewhat flattened. The scales on the cap are yellowish to tawny, and recurved. The stem is 4-12cm long by 0.5-1.5cm thick, and roughly equal in width throughout.
Although it may be edible, it is poisonous if consumed with alcohol, causing vomiting and diarrhoea after
about 10 hours.
It is thought to be a white rot fungus, which uses cellulose as a carbon source, and has the ability to degrade the lignin (present in wood) to carbon dioxide to access the cellulose molecule. It can attack a wide variety of deciduous host trees, including maple, birch, (especially) beech, and ash. It can also attack conifers, like spruce.
It is a secondary parasite, attacking trees already weakened from prior injury or infection by bacteria or other fungi. It also functions as a saprobe, obtaining nutrients by breaking down organic matter in dead wood.
It is used as a primary food source by the red squirrel Sciurus vulgaris, having higher protein content than other mushrooms it consumes. Decaying fruit bodies are also used as a food source by fruit flies of the genus Drosophila.
The fruit bodies have unique chemical compounds which inhibit the enzyme xanthine oxidase which catalyzes crystallization of uric acid in the joints - a main cause of gouty arthritis. Such inhibitors are being used clinically to reduce this effect.
See here for more info on this fungus.
See short videos here (numerous photos + strange music!), here (@ Hebden Bridge) and here (@ Dumfries House).
