The Agaricales are an order of fungi in the division Basidiomycota. As originally conceived, the order contained all the agarics, but subsequent research has shown that not all agarics are closely related and some belong in other orders, such as the Russulales and Boletales. Conversely, DNA research has also shown that many non-agarics, including some of the clavarioid fungi and gasteroid fungi belong within the Agaricales. The order has 46 extant families, more than 400 genera, and over 25,000 described species, along with six extinct genera known only from the fossil record. Species in the Agaricales range from the familiar Agaricus bisporus and the deadly Amanita virosa to the coral-like Clavaria zollingeri and bracket-like Fistulina hepatica.
The Agaricaceae are a family of basidiomycete fungi and include the genus Agaricus, as well as basidiomycetes previously classified in the families Tulostomataceae, Lepiotaceae, and Lycoperdaceae.
A basidiospore is a reproductive spore produced by Basidiomycete fungi, a grouping that includes mushrooms, shelf fungi, rusts, and smuts. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are produced by specialized fungal cells called basidia. Typically, four basidiospores develop on appendages from each basidium, of which two are of one strain and the other two of its opposite strain. In gills under a cap of one common species, there exist millions of basidia. Some gilled mushrooms in the order Agaricales have the ability to release billions of spores. The puffball fungus Calvatia gigantea has been calculated to produce about five trillion basidiospores. Most basidiospores are forcibly discharged, and are thus considered ballistospores. These spores serve as the main air dispersal units for the fungi. The spores are released during periods of high humidity and generally have a night-time or pre-dawn peak concentration in the atmosphere.
The Tricholomataceae are a large family of fungi within the order Agaricales. Originally a classic "wastebasket taxon", the family included any white-, yellow-, or pink-spored genera in the Agaricales not already classified as belonging to e.g. the Amanitaceae, Lepiotaceae, Hygrophoraceae, Pluteaceae, or Entolomataceae.
Melanoleuca is a poorly known genus of saprotrophic mushrooms traditionally classified in the family Tricholomataceae. Most are small to medium sized, white, brown, ocher or gray with a cylindrical to subcylindrical stipe and white to pale yellowish gills. The basidiospores are ellipsoid and ornamented with amyloid warts. Melanoleuca is considered a difficult group to study due to their macroscopic similarities among species and the need of a thorough microscopic analysis to separate species. DNA studies have determined that this genus is closely related to Amanita and Pluteus and that it does not belong to the family Tricholomataceae.
Crepidotus versutus, commonly known as the evasive agaric, is a species of fungus in the family Crepidotaceae. It is saprobic on wood, like other Crepidotus species, but it can also decompose herbaceous forest litter. The species is characterized by large, punctate, ellipsoid spores, and the white, hairy pileus.
Nidula is a genus of fungi in the family Agaricaceae. Their fruit bodies resemble tiny egg-filled birds' nests, from which they derive their common name "bird's nest fungi". Originally described in 1902, the genus differs from the related genera Cyathus and Crucibulum by the absence of a cord that attaches the eggs to the inside of the fruit body. The life cycle of this genus allows it to reproduce both sexually, with meiosis, and asexually via spores. Species in this genus produce a number of bioactive compounds, including 4-(p-hydroxyphenyl)-2-butanone, a major component of raspberry flavor and insect attractor used in pesticides.
The Mycenaceae are a family of fungi in the order Agaricales. According to the Dictionary of the Fungi, the family contains 10 genera and 705 species. This is one of several families that were separated from the Tricholomataceae as a result of phylogenetic analyses. Taxa in the Mycenaceae are saprobic, have a cosmopolitan distribution, and are found in almost all ecological zones. The family was circumscribed by Caspar van Overeem in 1926.
Limnoperdon is a fungal genus in the monotypic family Limnoperdaceae. The genus is also monotypic, as it contains a single species, the aquatic fungus Limnoperdon incarnatum. The species, described as new to science in 1976, produces fruit bodies that lack specialized structures such as a stem, cap and gills common in mushrooms. Rather, the fruit bodies—described as aquatic or floating puffballs—are small balls of loosely interwoven hyphae. The balls float on the surface of the water above submerged twigs. Experimental observations on the development of the fruit body, based on the growth on the fungus in pure culture, suggest that a thin strand of mycelium tethers the ball above water while it matures. Fruit bodies start out as a tuft of hyphae, then become cup-shaped, and eventually enclose around a single chamber that contains reddish spores. Initially discovered in a marsh in the state of Washington, the fungus has since been collected in Japan, South Africa, and Canada.
Dendrocollybia is a fungal genus in the family Tricholomataceae of the order Agaricales. It is a monotypic genus, containing the single species Dendrocollybia racemosa, commonly known as the branched collybia or the branched shanklet. The somewhat rare species is found in the Northern Hemisphere, including the Pacific Northwest region of western North America, and Europe, where it is included in several Regional Red Lists. It usually grows on the decaying fruit bodies of other agarics—such as Lactarius and Russula—although the host mushrooms may be decayed to the point of being difficult to recognize.
Coprinites is an extinct monotypic genus of gilled fungus in the Agaricales family Agaricaceae. At present it contains the single species Coprinites dominicana.
Archaeomarasmius is an extinct genus of gilled fungus in the Agaricales family Tricholomataceae, containing the single species Archaeomarasmius leggetti. It is known from two fruit bodies recovered from amber, one consisting of a complete cap with a broken stem, the other consisting of a fragment of a cap. The cap has a diameter ranging from 3.2 to 6 mm, while the stem is 0.5 mm (0.02 in) thick. Spores were also recovered from the amber, and are broadly ellipsoid to egg-shaped, measuring roughly 7.3 by 4.7 μm. The species, which resembles the extant genera Marasmius and Marasmiellus, is inferred to have been saprobic on plant litter or other forest debris.
Aureofungus is an extinct monotypic genus of gilled fungus in the order Agaricales. At present it contains the single species Aureofungus yaniguaensis.
Protomycena is an extinct monotypic genus of gilled fungus in the family Mycenaceae, of order Agaricales. At present it contains the single species Protomycena electra, known from a single specimen collected in an amber mine in the Cordillera Septentrional area of the Dominican Republic. The fruit body of the fungus has a convex cap that is 5 mm (0.2 in) in diameter, with distantly spaced gills on the underside. The curved stipe is smooth and cylindrical, measuring 0.75 mm (0.030 in) thick by 10 mm (0.39 in) long, and lacks a ring. It resembles extant species of the genus Mycena. Protomycena is one of only five known agaric fungus species known in the fossil record and the second to be described from Dominican amber.
Mycetophagites is an extinct fungal genus of mycoparasitic in the order Hypocreales. A monotypic genus, it contains the single species Mycetophagites atrebora.
Entropezites is an extinct monotypic genus of [hypermycoparasitic] fungus in the order Hypocreales. At present it contains the single species Entropezites patricii.
Volvariella surrecta, commonly known as the piggyback rosegill, is an agaric fungus in the family Pluteaceae. Although rare, the species is widely distributed, having been reported from Asia, North America, Northern Africa, Europe, and New Zealand. The fungus grows as a parasite on the fruit bodies of other gilled mushrooms, usually Clitocybe nebularis. V. surrecta mushrooms have white or greyish silky-hairy caps up to 8 cm (3.1 in) in diameter, and white gills that turns pink in maturity. The stipe, also white, is up to 9 cm (3.5 in) long, and has a sack-like volva at its base.
Volvopluteus michiganensis is a species of mushroom in the family Pluteaceae. It was originally described under the name Pluteus michiganensis but molecular studies have placed it in the Volvopluteus, a genus described in 2011. The cap of this mushroom is about 7–9 cm (2.8–3.5 in) in diameter, gray, and has a cracked margin that is sticky when fresh. The gills start out as white but they soon turn pink. The stipe is white and has a volva at the base. Microscopical features and DNA sequence data are of great importance for separating this taxon from related species. V. michiganensis is a saprotrophic fungus that was originally described as growing on sawdust. It has only been reported from Michigan (US) and the Dominican Republic.
Volvopluteus asiaticus is a species of mushroom in the Pluteaceae family. The cap of this mushroom is about 70–90 mm (2.8–3.5 in) in diameter, greyish brown to brown. The gills start out white but they soon turn pink. The stipe is white and has a volva at the base. Microscopical features and DNA sequence data are of great importance for separating this taxon from related species. V. asiaticus is a saprotrophic fungus that was originally described as growing on the ground, in the humus layer. It is only known from Hokkaido (Japan).
