The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp (fungal fruiting body) that supports a spore-bearing surface, the hymenium. [1] The hymenium (hymenophore) may consist of lamellae, tubes, or teeth, on the underside of the pileus. A pileus is characteristic of agarics, boletes, some polypores, tooth fungi, and some ascomycetes.
Pilei can be formed in various shapes, and the shapes can change over the course of the developmental cycle of a fungus. The most familiar pileus shape is hemispherical or convex. Convex pilei often continue to expand as they mature until they become flat. Many well-known species have a convex pileus, including the button mushroom, various Amanita species and boletes.
Some, such as the parasol mushroom, have distinct bosses or umbos and are described as umbonate . An umbo is a knobby protrusion at the center of the cap. Some fungi, such as chanterelles have a funnel- or trumpet-shaped appearance. In these cases the pileus is termed infundibuliform.
In fungi, a basidiocarp, basidiome, or basidioma (pl. basidiomata) is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do not produce such structures. As with other sporocarps, epigeous (above-ground) basidiocarps that are visible to the naked eye are commonly referred to as mushrooms, while hypogeous (underground) basidiocarps are usually called false truffles.
Leccinum scabrum, commonly known as the rough-stemmed bolete, scaber stalk, and birch bolete, is an edible mushroom in the family Boletaceae, and was formerly classified as Boletus scaber. The birch bolete is widespread in Europe, in the Himalayas in Asia, and elsewhere in the Northern Hemisphere, occurring only in mycorrhizal association with birch trees. It fruits from June to October. This mushroom is also becoming increasingly common in Australia and New Zealand where it is likely introduced.
Inocybe is a large genus of mushroom-forming fungi with over 1400 species, including all forms and variations. Members of Inocybe are mycorrhizal, and some evidence shows that the high degree of speciation in the genus is due to adaptation to different trees and perhaps even local environments.
Tylopilus felleus, commonly known as the bitter bolete or the bitter tylopilus, is a fungus of the bolete family. Its distribution includes east Asia, Europe and eastern North America, extending south into Mexico and Central America. A mycorrhizal species, it grows in deciduous and coniferous woodland, often fruiting under beech and oak. Its fruit bodies have convex to flat caps that are some shade of brown, buff or tan and typically measure up to 15 cm (6 in) in diameter. The pore surface is initially white before turning pinkish with age. Like most boletes it lacks a ring and it may be distinguished from Boletus edulis and other similar species by its unusual pink pores and the prominent dark-brown net-like pattern on its stalk.
Rubroboletus pulcherrimus—known as Boletus pulcherrimus until 2015—is a species of mushroom in the family Boletaceae. It is a large bolete from Western North America with distinguishing features that include a netted surface on the stem, a red to brown cap and stem color, and red pores that stain blue upon injury. Until 2005 this was the only bolete that has been implicated in the death of someone consuming it; a couple developed gastrointestinal symptoms in 1994 after eating this fungus with the husband succumbing. Autopsy revealed infarction of the midgut.
Xerula megalospora is a species of gilled mushroom in the family Physalacriaceae.
Crepidotus versutus, commonly known as the evasive agaric, is a species of fungi 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.
Agaricus semotus is a woodland mushroom of the fungus order Agaricales. It, like many of its relatives, can be found spread throughout wooded, moist areas in the southern United States, and has been found in areas ranging from California to Florida; it is also indigenous to Great Britain and Europe. A. semotus has also been collected in New Zealand. Although various authors disagree about its edibility, its modest size prevents it from being a significant source of nutrition.
Exsudoporus frostii, commonly known as Frost's bolete or the apple bolete, is a bolete fungus first described scientifically in 1874. A member of the family Boletaceae, the mushrooms produced by the fungus have tubes and pores instead of gills on the underside of their caps. Exsudoporus frostii is distributed in the eastern United States from Maine to Georgia, and in the southwest from Arizona extending south to Mexico and Costa Rica. A mycorrhizal species, its fruit bodies are typically found growing near hardwood trees, especially oak.
Aureoboletus mirabilis, commonly known as the admirable bolete, the bragger's bolete, and the velvet top, is an edible species of fungus in the Boletaceae mushroom family. The fruit body has several characteristics with which it may be identified: a dark reddish-brown cap; yellow to greenish-yellow pores on the undersurface of the cap; and a reddish-brown stem with long narrow reticulations. Aureoboletus mirabilis is found in coniferous forests along the Pacific Coast of North America, and in Asia. Unusual for boletes, A. mirabilis sometimes appears to fruit on the wood or woody debris of Hemlock, suggesting a saprobic lifestyle. Despite occasional appearances to the contrary, Aureoboletus mirabilis is mycorrhizal, and forms close mutualistic associations with hemlock roots.
Xerocomellus zelleri, commonly known as Zeller's bolete, is an edible species of mushroom in the family Boletaceae. First described scientifically by American mycologist William Alphonso Murrill in 1912, the species has been juggled by various authors to several genera, including Boletus, Boletellus, and Xerocomus. Found solely in western North America from British Columbia south to Mexico, the fruit bodies are distinguished by their dark reddish brown to nearly black caps with uneven surfaces, the yellow pores on the underside of the caps, and the red-streaked yellow stems. The fungus grows in summer and autumn on the ground, often in Douglas fir forests or on their margins. The development of the fruit bodies is gymnocarpic, meaning that the hymenium appears and develops to maturity in an exposed state, not enclosed by any protective membrane.
Psilocybe makarorae is a species of psilocybin mushroom in the family Hymenogastraceae. Officially described as new to science in 1995, it is known only from New Zealand, where it grows on rotting wood and twigs of southern beeches. The fruit body (mushroom) has a brownish cap with lighter coloured margins, measuring up to 3.5 cm (1.4 in) wide. The cap shape is either conical, bell-shaped, or flat depending on the age of the mushroom, and it features a prominent umbo. Although the whitish stem does not form a true ring, it retains remnants of the partial veil that covers and protects the gills of young fruit bodies. P. makarorae mushrooms can be distinguished from the similar North American species Psilocybe caerulipes by microscopic characteristics such as the presence of cystidia on the gill faces (pleurocystidia), and cheilocystidia with more elongated necks. Based on the bluing reaction to injury, P. makarorae is presumed to contain the psychedelic compounds psilocybin and psilocin.
Suillus pungens, commonly known as the pungent slippery jack or the pungent suillus, is a species of fungus in the genus Suillus. The fruit bodies of the fungus have slimy convex caps up to 14 cm (5.5 in) wide. The mushroom is characterized by the very distinct color changes that occur in the cap throughout development. Typically, the young cap is whitish, later becoming grayish-olive to reddish-brown or a mottled combination of these colors. The mushroom has a dotted stem (stipe) up to 7 cm (2.8 in) long, and 2 cm (0.8 in) thick. On the underside on the cap is the spore-bearing tissue consisting of minute vertically arranged tubes that appear as a surface of angular, yellowish pores. The presence of milky droplets on the pore surface of young individuals, especially in humid environments, is a characteristic feature of this species. S. pungens can usually be distinguished from other similar Suillus species by differences in distribution, odor and taste. The mushroom is considered edible, but not highly regarded.
Mycena maculata, commonly known as the reddish-spotted Mycena, is a species of fungus in the family Mycenaceae. The fruit bodies, or mushrooms, have conic to bell-shaped to convex caps that are initially dark brown but fade to brownish-gray when young, reaching diameters of up to 4 cm. They are typically wrinkled or somewhat grooved, and have reddish-brown spots in age, or after being cut or bruised. The whitish to pale gray gills also become spotted reddish-brown as they mature. The stem, up to 8 cm (3 in) long and covered with whitish hairs at its base, can also develop reddish stains. The mycelium of M. maculata has bioluminescent properties. The saprobic fungus is found in Europe and North America, where it grows in groups or clusters on the rotting wood of both hardwoods and conifers. The edibility of the fungus is unknown. Although the species is known for, and named after its propensity to stain reddish, occasionally these stains do not appear, making it virtually indistinguishable from M. galericulata.
Boletus rubroflammeus is a species of bolete fungus in the family Boletaceae. First described from Michigan in 1971, it is found in the eastern United States and Mexico, where it grows in a mycorrhizal association with hardwood trees. The fruit bodies (mushrooms) of the fungus have caps that are deep red to purplish red, and dark red pores. The stem has coarse, dark red reticulations and a narrow yellow area at the top. All parts of the mushroom quickly stain blue when injured or cut. Lookalikes include Boletus flammans, a lighter-colored species that grows with conifers. Other similar species can be distinguished by differences in distribution, morphology, staining reaction, and microscopic characteristics. Boletus rubroflammeus mushrooms are poisonous, and can cause gastrointestinal distress if consumed.
Inocybe saliceticola is a fungus found in moist habitats in the Nordic countries. The species produces brown mushrooms with caps of varying shapes up to 40 millimetres (1.6 in) across, and tall, thin stems up to 62 mm (2.4 in) long. At the base of the stem is a large and well-defined "bulb". The species produces unusually shaped, irregular spores, each with a few thick protrusions. This feature helps differentiate it from other species that would otherwise be similar in appearance and habit.
Boletus curtisii is a species of fungus in the family Boletaceae. It produces small- to medium-sized fruit bodies (mushrooms) with a convex cap up to 9.5 cm (3.7 in) wide atop a slender stem that can reach a length of 12 cm (4.7 in). In young specimens, the cap and stem are bright golden yellow, although the color dulls to brownish when old. Both the stem and cap are slimy or sticky when young. On the underside of the cap are small circular to angular pores. The mushroom is edible, but not appealing. It is found in eastern and southern North America, where it grows in a mycorrhizal association with hardwood and conifer trees. Once classified as a species of Pulveroboletus, the yellow color of B. curtisii is a result of pigments chemically distinct from those responsible for the yellow coloring of Pulveroboletus.
Boletus auripes, commonly known as the butter-foot bolete, is a species of bolete fungus in the family Boletaceae. First described from New York in 1898, the fungus is found in eastern Asia, Central America, and eastern North America from Canada to Florida. It is a mycorrhizal species and typically grows in association with oak and beech trees.
Austroboletus olivaceoglutinosus is a species of bolete fungus found in Sikkim in northeast India. It is so named for its sticky olive-green cap.
Pseudocraterellus undulatus is a species of fungus belonging to the family Hydnaceae. It has the common name sinuous chanterelle.
