There are over 200 European species identified within the family Agaricaceae; more than fifty are detailed via the gallery links below.
Most fungi within this family have caps with gills, and they have stalks either attached at the centre of the cap or, in some instances, off centre. Most Agaricaceae grow on soil or leaf litter, but a few (generally smaller species) are to be found on rotting wood.
The two largest genera in this family are Agaricus and Lepiota. The family also includes some small genera including Chlorophyllum, Macrolepiota, Coprinus (which now excludes most of the inkcaps) and a few others. Not by any means are all of the fungi in this family good or even safe to eat, although the Agaricaceae does include some prized edible species.
The gills of Agaricus mushrooms are free and crowded, and the spores are dark brown. Nearly all species in the genus smell very much like the cultivated mushroom, although there are a few with an aniseed odour and at least one with an unpleasant inky smell.
This genus contains several edible species including the Field Mushroom, Agaricus campestris, and the Cultivated Mushroom, Agaricus bisporus - the two mushrooms most used often in British cuisine. Many other species in this genus are good edible mushrooms, but the group does also contain other fungi capable of causing stomach upsets or, in some cases, more serious symptoms.
Fungi in these genera have white or very pale free gills, a stem ring left by the partial veil, white spores, and a cap surface that is broken into scales.
The Parasol Macrolepiota procera and several other species from this group are prized edible mushrooms, but the Chlorophyllum species are known to be poisonous. Beware also of confusion between small specimens of Macrolepiota mushrooms and some of the Lepiota fungi, commonly known nowadays as dapperlings (see below), which are also either known to be poisonous or at least are suspect and worthy of being treated as inedible.
Fungi in this genus have white or very pale free gills, often a stem ring left by the partial veil (although the ring is transient in several instances), white spores, and usually (but not always) a cap surface that is broken into small scales.
Few if any dapperlings are good edible mushrooms, and most of the smaller species are either known to be poisonous or at least suspect. Lepiota cristata, the Stinking dapperling, is one such example, and it has been known to cause serious poisoning. Another member of the family Agaricaceae now thought to be slightly toxic is Leucoagaricus leucothites, the White Dapperling.
It's hardly what anyone would have expected, but molecular studies have shown that the puffballs and a few other gasteromycetes or 'stomach fungi' are very closely related to gilled mushrooms in the Agaricaceae, and so such families as Lycoperdaceae and Tulostomataceae (stiltballs, also known as stilt puffballs) are being dismantled as the fungi therein are moved into the Agaricaceae.
Bird's nest fungi such as Crucibulum laeve are also now placed in the family Agaricaceae, although some authorities still retain their former family Nidulariaceae.
For more information about the family Agaricaceae and a deeper insight into the ecology and structure of the Agaricus and other species featured in our Agaricaceae Gallery pages, please see Pat O'Reilly's latest book Fascinated by Fungi, author-signed copies of which are available online here...
The Genus Agaricus in Great Britain, a monograph published in 2011 by Geoffrey Kibby, is a first-class up-to-date technical guide, with dichotomous keys, to the common and rare Agaricus species found in Britain.