Turns yellow when bruised

This poisonous mushroom has been introduced into Australia. It is very common and widely distributed in North America and Europe, and is also found in North Africa. Similar to the common field mushroom, but recognisable for its tendency to stain and bruise yellow and by its characteristic unpleasant odour. The surfaces that have bruised yellow eventually turn brownish, helping to distinguish this mushroom from others that bruise yellow and remain yellowed. Cap 6-20 cm, round to irregularly convex, becoming broadly convex or nearly flat, whitish, or with light brown colorations, especially towards the centre. In the photos at right (see Yellow stains shown below) the top strip shows a broken cap, which immediately stains yellow upon exposure to the air. The middle photo shows the more intense staining of the stalk (the end in the ground) and the third strip shows a young cap with the skin peeled back, which stains immediately also. The younger ones stain less. Gills free from the stem white at first, then pinkish, and finally dark chocolate brown. Stem 5-18 cm long, 1-3 cm thick, more or less equal, sometimes enlarged at the base. Spore print is dark chocolate brown. The cap is usually dry, smooth but sometimes becoming scaly in age.

Gills. Photo: Robert Whyte

Scaly with age. Photo: Robert Whyte

Mature mushroom from above. Photo: Robert Whyte

Yellow stains. Photo: Robert Whyte