Pleurotus dryinus
Pleurotus dryinus, commonly known as the veiled oyster mushroom, is a species of fungus in the family Pleurotaceae. It grows on dead wood and is a weak pathogen, especially infecting broad-leaved trees.
Taxonomy
The original definition of this fungus as Agaricus dryinus was made by Christian Hendrik Persoon in 1800. In 1871, Paul Kummer introduced Pleurotus as a genus and defined three similar ringed species: Pleurotus corticatus, Pleurotus albertini and P. dryinus. They were distinguished because only P. corticatus has intertwined gills on the stem and P. albertini is bigger and grows on conifer wood rather than oak. All three are now considered to be forms of the same species. The name dryinus takes precedence because it is the oldest.Also, in 1874 Elias Magnus Fries defined a species as Pleurotus tephrotrichus, which has a deeper grey colour. This has also been incorporated into P. dryinus but may be distinguished as the variety tephrotrichus.
Etymology
The species name is a Latinised version of the Greek word "dryinos", meaning "related to oak", referring to one of its main hosts.Description
The cap grows to across. It is pale to beige, but can turn yellowish. Veil remnants may adhere to the edge. At first it is velvety and the tomentum can develop into grey-brown scales; in old specimens the surface becomes bare and may crack.The whitish or pale brownish lateral stem may be very short or up to 10 cm long, generally with a membranous ring.
The gills are decurrent well down the stipe and may anastomose at the lower extreme. They are white, sometimes turning yellowish.
The smell is described as "pleasant" or "slightly polypore-like" or "complex, a bit fruity or sourish". The taste is mild.
Microscopic characteristics
As with ordinary fragile mushrooms, the flesh may be monomitic but may be dimitic, having extra thick-walled hyphae which give the flesh a tough consistency. There are no cystidia.The spores are elongated in the form of a rounded cylinder and around 9–15 μm by 3–5 μm.
Distribution and habitat
Appearing from summer to autumn, it is distributed throughout Europe, where it varies locally between common and rare. It is also found in North America.This mushroom is saprobic on dead wood and can also be a weak parasite of trees. It occurs especially on oak, but also on beech, other broad-leaved trees, and occasionally on conifers. It is often solitary or may grow in small groups.
Uses
This mushroom is edible, though it is tough when older and inferior to the better-known members of Pleurotus.Like some other Pleurotus species, P. dryinus attacks nematodes and may provide a control method for these parasites when they infect cats and dogs.