Agaric in the context of "Pileus (mycology)"

The Basidiomycota (/bəˌsɪdi.oʊmaɪˈkoʊtə/) are one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. This division includes: agarics, puffballs, stinkhorns, bracket fungi, other polypores, jelly fungi, boletes, chanterelles, earth stars, smuts, bunts, rusts, mirror yeasts, and Cryptococcus, the human pathogenic yeast.

Basidiomycota are filamentous fungi composed of hyphae (except for basidiomycota-yeast) and reproduce sexually via the formation of specialized club-shaped end cells called basidia that normally bear external meiospores (usually four). These specialized spores are called basidiospores. However, some Basidiomycota are obligate asexual reproducers. Basidiomycota that reproduce asexually (discussed below) can typically be recognized as members of this division by gross similarity to others, by the formation of a distinctive anatomical feature (the clamp connection), cell wall components, and definitively by phylogenetic molecular analysis of DNA sequence data.

In mycology, a lamella (pl.: lamellae), or gill, is a papery hymenophore rib under the cap of some mushroom species, most often agarics. The gills are used by the mushrooms as a means of spore dispersal, and are important for species identification. The attachment of the gills to the stem is classified based on the shape of the gills when viewed from the side, while color, crowding and the shape of individual gills can also be important features. Additionally, gills can have distinctive microscopic or macroscopic features. For instance, Lactarius species typically seep latex from their gills.

It was originally believed that all gilled fungi were Agaricales, but as fungi were studied in more detail, some gilled species were demonstrated not to be. It is now clear that this is a case of convergent evolution (i.e. gill-like structures evolved separately) rather than being an anatomic feature that evolved only once. The apparent reason that various basidiomycetes have evolved gills is that it is the most effective means of increasing the ratio of surface area to mass, which increases the potential for spore production and dispersal.

Agaricomycotina is one of three subdivisions of the Basidiomycota (fungi bearing spores on basidia), and represents many fungi which form macroscopic fruiting bodies. Agaricomycotina contains over 30,000 species, divided into three classes: Tremellomycetes, Dacrymycetes, and Agaricomycetes. Around 98% of the species are in the class Agaricomycetes, including all the agarics (gilled mushrooms), bracket fungi, clavarioid fungi, corticioid fungi, and gasteroid fungi. Tremellomycetes contains many basidiomycete yeasts and some conspicuous jelly fungi. Dacrymycetes contains a further group of jelly fungi. These taxa are founded on molecular research, based on cladistic analysis of DNA sequences, and supersede earlier morphology-based classifications. Agaricomycotina contains nearly one third of all described species of fungi.

The class Bartheletiomycetes contains a single anomalous species of basidiomycete which grows on fallen leaves of Ginkgo biloba. Some researchers suggest that this class should be included in Agaricomycotina.

The genus Amanita contains about 600 species of agarics, including some of the most toxic known mushrooms found worldwide, as well as some well-regarded edible species (and many species of unknown edibility). The genus is responsible for approximately 95% of fatalities resulting from mushroom poisoning, with the death cap accounting for about 50% on its own. The most potent toxin synthesized by this genus is α-Amanitin.

The genus also contains many edible mushrooms, but mycologists discourage mushroom hunters from selecting any of these for human consumption due to the potentially lethal consequences of misidentification. Nonetheless, in some cultures, the larger local edible species of Amanita are mainstays of the markets in the local growing season. Samples of this are Amanita zambiana and other fleshy species in central Africa, A. basii and similar species in Mexico, A. caesarea and the "Blusher" A. rubescens in Europe, and A. chepangiana in Southeast Asia. Other species are used for colouring sauces, such as the red A. jacksonii, with a range from eastern Canada to eastern Mexico.