Pale Oyster

Description

The pale oyster has a cap 5-12 cm across, spatula-shaped or shell-shaped, pale: cream or pale brown, grey-brown with age. The gills are whitish, crowded and run deeply down onto a short, eccentric stem that is thinner at the base. The flesh has a delicate smell of anise.

It grows from June to October, usually in numerous clusters on trunks and boughs of beeches, oaks and other broadleaved trees, both on dead wood and on living trees. It is rare in Poland. It is distinguished from the oyster mushroom, which fruits in late autumn, by its paler cap and summer growing season.

Only young fruiting bodies are collected, because older ones are often infested with insect larvae. If you are not sure of the species, do not pick or eat it.

Identification features

Cap

Diameter 5-12 cm (some descriptions give 5-20+ cm), spatula-shaped, oyster-shaped in younger ones, convex, later broadly convex to flat; margin rolled under, bent, sometimes ragged. Soft, thin-fleshed, pale: cream, pale brown, yellowing at the margin, grey-brown with age. Attached to the substrate sideways.

Hymenophore (underside of the cap)

Gills crowded, narrow, springy, running deeply down the stem, unforked, whitish or pale cream; they turn yellow as they dry. Small beetles may occur on them.

Stem

Height 1-6 cm, thickness 0.6-1.5 cm, eccentric, sometimes lateral, conical (thinner at the base), smooth, whitish surface, felty at the base. No ring.

Flesh

At first springy and delicate, hard with age, whitish. Smell indistinct, pleasant, reminiscent of anise; taste sweetish.

Spore print and spores

Spore print white with a violet tinge (according to some descriptions white, greyish or lilac). Spores cylindrical, 7.5-11 × 3-4 µm.

Habitat and distribution

Ecology. A saprotrophic and parasitic fungus; grows on dead wood and on living trees. Most often on trunks and boughs of beeches, also oaks and other broadleaved trees; in western North America also on conifers.

Distribution. Occurs on all continents except Antarctica and Africa (some descriptions give wide distribution in temperate and subtropical forests). Rare in Poland, on the 2006 Red List with status V (vulnerable to extinction). Not legally protected.

Fruiting. From June to October; usually in numerous clusters, sometimes singly. Prefers warmer weather than P. ostreatus and appears in the second half of summer.

What can it be confused with?

• Pleurotus ostreatus (oyster mushroom) — Fruits only in late autumn. Cap much darker and larger, stem less developed (according to some descriptions P. pulmonarius has much paler and smaller caps and a better developed stem).
• Crepidotus spp. (oysterlings) — Gills clay-brown in colour.
• Pleurotus populinus — A North American species, grows only on aspen and poplars (Populus).
• Clitocybe spp. (funnel caps; some poisonous) — May resemble a funnel cap when growing on top of wood; detailed differences - no data.
• Lentinus sajor-caju — Commercial strains of P. pulmonarius are sometimes wrongly identified as "Pleurotus sajor-caju"; L. sajor-caju has a ring on the stem, P. pulmonarius a bare stem.

Never rely on a single feature. If you are not sure — do not pick it; show the mushroom to a qualified mushroom expert.

Interesting facts

• The Polish name was given only by C. Narkiewicz in 2001.
• In New Zealand it is cultivated and sold as "oyster mushroom", because P. ostreatus cannot be imported there for fear of harm to forestry.
• Commercial strains are often wrongly identified as "Pleurotus sajor-caju", which is a synonym of Lentinus sajor-caju.
• In studies on mice the extract relieved hay fever symptoms only after several weeks of administration.