There are estimated to be more than 38,000 types of mushroom, some of which are poisonous, but most of which are edible. They fall into two types - cultivated and wild.
Some mushrooms are believed to have health-giving effects, from thinning the blood to preventing tumours. They are low in calories and are therefore a useful food to include in weight-loss diets,
Mushrooms contain about 1mg of iron per 100g. It is not much in the scheme of things (women need 14.8mg daily), but unlike some vegetable sources or iron, mushrooms do not contain phytates, a type of fibre which disrupts its absorption.