Assorted mushrooms. Several edible mushrooms are shown with some spring onions and lemons at right. Oyster mushrooms (fan-shaped) are at centre. There are shiitake mushrooms in the small bowl above the oyster mushrooms, and also at far left. Field mushrooms are at top left, bottom centre, and also on the chopping board at lower right. Small button mushrooms (champignons) are above at right of the oyster mushrooms. Mushrooms are fruiting bodies of fungi. They are a good source of protein, minerals (including potassium, phosphate, iron and sulphur) and carbohydrates. Oyster and shiitake mushrooms contain anti-cancer chemicals.