Lentinula edodes
A rich, savoury, wood-loving mushroom with a meaty brown cap — cultivated in East Asia for centuries and now one of the most widely grown mushrooms in the world.
Shiitake are native to the forests of East Asia, where they grow on dead and dying hardwood trees such as oak and chestnut. The name comes from Japanese: "shii" is a type of tree they grow on, and "take" means mushroom. The cap is usually brown, about 2 to 4 inches across, with edges that curl under and pale gills beneath.
Like oysters, they're saprotrophs — they feed on dead wood rather than living plants. Unlike oysters, shiitake usually grow as single caps scattered along a log instead of in overlapping shelves. In cultivation, they're grown on hardwood logs or on blocks of hardwood sawdust.
A mature shiitake releases millions of microscopic spores from the gills under its cap. Carried by air currents, most land somewhere with no chance of growing — but a few reach a damp piece of hardwood with the right food inside it.
A spore that lands somewhere favorable germinates, sending out a fine thread called a hypha. On its own, a single hypha can't reproduce — it needs to meet and fuse with a compatible hypha from another spore.
Once two compatible hyphae fuse, the resulting network grows outward as mycelium — a web of fine white threads that spreads through the wood or sawdust, digesting it and absorbing the nutrients. On a sawdust block, the surface eventually turns brown as the mycelium forms a protective skin.
When the mycelium has fully colonized its food source and conditions shift — a drop in temperature, a soak in cool water, fresh air — it forms tiny knots of tissue called primordia, or "pins." This is the first visible sign a mushroom is coming.
Pins that get enough humidity and airflow swell into full mushrooms — the brown, domed caps with curled edges that we recognize and harvest. This is the fruiting body: a temporary structure whose only job is to make spores.
As the cap matures and flattens out, its gills release a new generation of spores into the air, and the cycle begins again. In cultivation, shiitake are picked just before this point, while the cap edges are still curled under.