Mushroom Classification: Unlocking The Secrets Of Fungi

Mushrooms are fleshy, spore-bearing fruiting bodies of fungi that typically grow above ground on soil or another food source. The scientific classification of mushrooms involves grouping them hierarchically based on shared characteristics, ranging from broader categories like Kingdom and Phylum to more specific classifications like Genus and Species. The standard for the name mushroom is the cultivated white button mushroom, Agaricus bisporus, which has a stem (stipe), a cap (pileus), and gills (lamellae) under the cap. Mushrooms can also be categorized into common groups based on shared features, primarily their shape and reproductive methods. For example, puffballs, earthstars, and stinkhorns are categorized separately from gilled mushrooms due to their unique structures and spore dispersal methods.

Scientific classification: Kingdom, Phylum, Class, Order, Family, Genus, Species

Mushrooms are classified based on their shape and reproductive methods. The scientific classification of mushrooms, like all organisms, is a hierarchical system where each mushroom is grouped based on shared characteristics. The classification goes as follows:

Kingdom

Mushrooms belong to the Kingdom Fungi.

Phylum

The Phylum of mushrooms varies. For example, the Phylum of the commonly cultivated mushroom, Agaricus bisporus, is Basidiomycota, whereas the Phylum of the morel mushroom is Ascomycota.

Class

The Class of mushrooms varies. For example, the Class of the Agaricus bisporus is Agaricomycetes, whereas the Class of the morel mushroom is also Ascomycota.

Order

The Order of mushrooms varies. For example, the Order of the Agaricus bisporus is Agaricales, whereas the Order of the chanterelle mushroom is Cantharellales.

Family

The Family of mushrooms varies. For example, the Family of the Agaricus bisporus is Agaricaceae, whereas the Family of the milk-cap mushroom is Russulaceae.

Genus

The Genus of mushrooms varies. For example, the Genus of the Agaricus bisporus is Agaricus, whereas the Genus of the panther cap mushroom is Amanita.

Species

The Species of mushrooms varies. For example, the Species of the Agaricus bisporus is bisporus, whereas the Species of the magic mushroom is Psilocybe cubensis.

It is important to note that the classification of mushrooms can be complex and may change over time as new information is discovered.

Common mushroom groups: gilled, boletes, puffballs, earthstars, stinkhorns

Mushrooms are classified based on their shared characteristics, with each classification offering more specificity. The term "mushroom" is often used to refer to those fungi that have a stem (stipe), a cap (pileus), and gills (lamellae) on the underside of the cap. These gills are the reproductive parts of the mushroom and produce microscopic spores, which help the fungus spread. Mushrooms that do not have gills are more loosely referred to as mushrooms, and their specific classification can be more challenging. Some common mushroom groups include:

Gilled Mushrooms

Gilled mushrooms, also known as agarics, come in a wide variety of sizes, colours, and characteristics. They include some of the best-known edible mushrooms, such as honeys, blewits, parasols, and meadow mushrooms. However, they also include deadly poisonous varieties, such as Amanitas and Galerinae. The gills of these mushrooms can be close, distant, smooth, or serrated, and the caps can vary in texture, including velvety, slimy, scaly, or fuzzy. The spore colours can be white, pink, brown, or purple-black. Gilled mushrooms can be found growing on the ground or on wood, and they may grow singly or in clusters.

Boletes

Boletes, or boletus species (Boletaceae), are another common group of mushrooms. They have fleshy caps and a central stalk, but instead of gills, they have a spongy layer of tubes underneath their caps. These tubes produce spores, which are then released and dispersed by the wind. Many species of boletes are edible and highly sought-after in culinary dishes worldwide, such as the King Bolete or Porcini. However, a few species are poisonous, typically identified by their red or deep orange pores. Boletes often resemble gilled mushrooms from the top but can be distinguished by their spongy or pored underside.

Puffballs

Puffballs (Lycoperdales) are odd-looking fungi that produce spores inside round or oblong sacs. They lack a stalk but may have a supporting base. As puffballs mature, their interior turns brown and fills with spores, becoming dry and powdery. Eventually, a small hole forms, and wind or rain puffs out the spores, giving them their namesake. Some puffballs are edible, but it is crucial to ensure they are pure white inside before consumption.

Earthstars

Earthstars are small fungi that resemble flying saucers when young. They are shaped like a ball initially, but as they mature, the surface splits open, releasing spores through the top. The pieces then curve back, forming arms that resemble a star. Earthstars are distributed throughout North America and are known for their strong smell and colourful, odd shapes. They are similar to puffballs in structure and spore production but differ in their distinctive star-like appearance.

Stinkhorns

Stinkhorns are exotic mushrooms that are easily recognisable by their phallic appearance and bright colours. They first appear as eggs that resemble puffballs, but as they mature, they develop into fanciful shapes. Stinkhorns produce a foul-smelling, sticky spore mass on their caps, which attracts insects. These insects then spread the spores to new locations. The smell of some stinkhorns is likened to rotting meat, attracting flies and beetles that aid in spore dispersal.

Toadstools: poisonous or inedible mushrooms

The term "toadstool" is an unscientific label sometimes applied to certain types of mushrooms. Toadstools are generally considered to be inedible or poisonous mushrooms. However, it's important to note that there is no scientific distinction between a toadstool and a mushroom. The term "mushroom" is typically used to refer to edible fungi, while "toadstool" is often used for inedible or poisonous varieties.

The standard for the name "mushroom" is the cultivated white button mushroom (*Agaricus bisporus*). Mushrooms are typically white-capped species that grow in fields and are generally safe to eat. They are characterised by their domed caps on stalks, with gills on the underside of the cap. Mushrooms can also include varieties like oyster mushrooms or puffballs, which don't necessarily have the traditional mushroom shape.

Toadstools, on the other hand, are often associated with colourful and distinct-looking toxic mushrooms, such as the red *Amanita muscaria*. They are believed to be inedible or toxic, with consumption potentially causing minor gastrointestinal infections, psychosomatic issues, or even death. In some cultures, toadstools are considered to be shelf fungi that grow on trees.

Identifying edible mushrooms from toadstools can be challenging and dangerous. While modern identification methods are becoming increasingly molecular, traditional identification methods are still widely used. These methods consider various factors such as the presence of juices, bruising reactions, odours, tastes, shades of colour, habitat, season, and other context-specific details. However, relying solely on terms like "mushroom" or "toadstool" to determine edibility is not recommended. Accurate identification requires an experienced mushroom hunter who can consider biological features like spore prints and gills, as well as the specific geographical and seasonal context of the mushroom's growth.

The scientific classification of mushrooms follows a hierarchical system, grouping organisms based on shared characteristics. This classification includes categories such as Kingdom, Phylum (or Division), Class, Order, Family, Genus, and Species. Each step in the classification provides more specificity, allowing for clear identification of unique combinations of genus and species names across global scientific communities.

Spores: colour, microscopic features, dispersal by wind or insects

Mushrooms are the fleshy, spore-bearing fruiting bodies of fungi, typically produced above ground on soil or another food source. The spores are called basidiospores and are produced on the gills, falling in a fine rain of powder from under the caps. The gills may change colour as the mushroom grows and the spores mature. For instance, the gills of a mushroom may change from white to a dark purplish brown. The simplest way to determine a mushroom's spore colour is to examine its gills or pores, as the spores colour them as they mature.

Spore colour can vary, with the most common colours being white, brown, black, purple-brown, pink, yellow, and creamy. Less common colours include orange, green, and blue. The colour of the spores, or spore print, is useful in classifying and identifying mushrooms. To create a spore print, one can invert a cup or bowl over the mushroom cap to keep the spores from blowing around.

While the wind is a common method of spore dispersal, mushrooms themselves can also generate airflow to distribute spores, a process known as evaporative cooling. Small water droplets appear on mushrooms before spore dispersal, creating enough vapour to lift and spread the spores. Insects also play a role in spore dispersal. For instance, stinkhorn mushrooms have spores contained in a foul-smelling, sticky slime that attracts flies, which then carry the spores elsewhere.

Morphology: shape, stalk, gills, spores, cap

Mushrooms are typically categorized based on their morphology, or the study of their form and structure. This includes examining their shape, stalk, gills, spores, and cap.

The shape, stalk, gills, spores, and cap of a mushroom are all important characteristics that aid in the identification and categorization of mushrooms.

Cap

The cap, or pileus, is the umbrella-like structure that sits atop the stem. It serves as a protective covering for the delicate gills, pores, and spore-bearing surfaces beneath. The shape of the cap can vary widely, from commonly observed convex shapes to more peculiar forms like the cuspidate, or witch-hat shape. Other shapes include egg-shaped, cone-shaped, bell-shaped, and saucer-shaped, among others. The cap's surface texture, margins (edge), color, height, width, and viscosity are also important characteristics to consider.

Stalk

The stalk, also known as the stipe or stem, functions as a pillar that elevates the cap above the ground. It may be central and support the cap in the middle, or it may be off-center or lateral, as in some species. Some mushrooms, like puffballs and truffles, may lack a distinct stalk. The shape of the stalk can vary, ranging from cylindrical to more irregular forms. Other characteristics to note are the surface texture, color, durability, interior, orientation, volva, and bulb.

Gills

Gills, or lamellae, are the structures on the underside of the cap that produce microscopic spores, aiding in the fungus's spread. Some mushrooms form a single array of unbranched radial gills, while others produce multiple files of lamellulae (short gills) between the primary gills, and branched gills are also common. The way the gills attach to the top of the stalk is an important feature of mushroom morphology. Some mushrooms have free gills that do not extend to the top of the stalk, while others have decurrent gills that extend down the stalk.

Spores

Spores are produced on the gills and are released when the mushroom matures, starting the life cycle anew. These spores fall in a fine rain of powder from under the caps. The color of the spore print, or the powdery residue, is useful for classifying and identifying mushrooms. Common colors include white, brown, black, purple-brown, pink, yellow, and creamy, while blue, green, and red are rarely observed.

Understanding the morphology of a mushroom, including its shape, stalk, gills, spores, and cap, is essential for accurate identification and categorization. It also provides insights into the ecological roles and potential uses of different mushroom species.

Frequently asked questions