Agaricus

The common name is Wood Mushroom or simply Mushroom, and the shop and field mushrooms are members of this genus. Many species discolour either yellowish or distinctly red or pinkish when bruised or cut. The young gills are pink or, in some species, white at first. Some species have an aniseed smell. Most are edible, but those bruising bright yellow should be carefully checked. The species that are known to cause severe stomach upsets normally show a distinct yellow colour change at the base of the stem on cutting, but the specimens will need to be very fresh for you to observe this.