Shelling out – The Oyster mushroom
It’s good to know some mushrooms can appear all year round, especially when they’re edible and good. It’s nearly always the right time to look out for these beauties…
In this case it’s the common and most welcome Oyster Mushroom (Pleurotus ostreatus). Usually growing in medium to large clusters on fallen logs, stumps or standing trunks, it’s one mushroom I always look out for during the ‘out of season‘ months. I mainly choose deciduous woods to visit (some can grow on coniferous wood) where they are most commonly found, especially on beech.
And thankfully they are also one of the most recognisable species out there. The distinctive ‘shell’ shapes and lateral (often minimal or missing) stems with white decurrent gills are all typical characteristics. The caps are convex shaped when young but will flatten out as they grow, often becoming wavy or split at the margin. And just to note: very rarely will you see a ’rounded’ shaped cap, but it does happen.
There is one thing though that the Oyster mushroom is not reliable with – and that is it’s colour (just like my spellchecker telling me I’ve spelt color wrong!). The shades are quite variable, but tend to be in subtle shaded hues of grey/whitish-brown, blue-grey, violet-grey etc. As you can see in these photos, I have stumbled across the grey-brown kind. A variant of the Oyster mushroom named Pleurotus columbinus is more or less the same mushroom but with a striking and beautiful violet cap. I haven’t seen any of those though. Shame.
As most of us all know, Oyster mushrooms are one of the most popular mushrooms to eat on the planet. There are many different species of course, successfully cultivated and sold throughout the world. But here in the UK, you’re best and most reliable bet is our common Pleurotus ostreatus. Cook ’em up in a stir fry one night and enjoy – Happy hunting.

Two separate encounters of the wild ‘shell shaped’ Oyster mushroom. Top: A group of young examples growing on a fallen log. Bottom: Very large and older examples (approx 14-15cm across) growing from a standing trunk.
QUICK ID TABLE: OYSTER MUSHROOM Pleurotus ostreatus |
CAP / FLESH 6 – 20cm across. Shell shaped. Convex when young, flattening out. Often split or wavy margin. Subtle variable hues of grey-brown, whitish-brown, blue-grey, violet-grey. Flesh is born or blue-grey. STEM 2-3cm x 10-20cm. Excentric to lateral or abscent. White with a woolly base. GILLS / SPORE PRINT Decurrent. Initially white fading yellowish later. HABITAT / SEASON In medium to large clusters on stumps, fallen logs or standing trunks. Mostly deciduous trees such as birch. Sometimes on coniferous wood. All year round. EDIBILITY Edible and good. |
The Genus PLEUROTUS (Oyster): Characteristics to look out for: • Shell shaped fruting body with little or no visible stem. |