Boletales

Boletales is an order of fungi in the division Basidiomycota. It contains a large number of species with a wide variety of types of fruiting body or mushroom. The Boletus are the best-known genus of this order.

Taxonomy

Originally, the order Boletales was created to describe tickets. However, based on micromorphological characteristics and molecular DNA analyses, many species that show no similarity to boletus have been included in this group. The order also includes some fungi that produce fruiting bodies with lamellae—included in the families Gomphidiaceae and Paxillaceae. The meat of these species often has the same texture as boletus, the tissue where the spores are produced is also easily separated from the cap, and their spores and cystidia—sterile cells designed to facilitate spore release—have similar microscopic characteristics.. Genetic studies have also caused other physically very different taxa to be placed in this group, such as the families Sclerodermataceae and Rhizopogonaceae.

Phylogenetic analyzes indicate that Sclerodermataceae, Boletinellaceae and Gyroporaceae seem to form a defined group within Boletales, which together with Pisolithaceae, Astraceae and Calostomataceae, constitute the suborder Sclerodermatineae. Thus, boletus of the genus Gyrodon and Phlebopus are more closely related to species of the genus Scleroderma than to those of the genus Boletus. Similarly, the genus Suillus is closest to the agarics and false truffles of Chroogomphus, Gomphidius, and Rhizopogon than to the genus Boletus.

In some classifications, part of the family Boletaceae is separated into the family Strobilomycetaceae. According to the 10th edition of the Dictionary of the Fungi (2008), Boletales comprise 17 families, 96 genera and 1316 species.

Ecology

Boletus parasiticus growing Scleroderma citrinum

Boletales are generally ectomycorrhizal fungi, and are therefore found mainly in or near wooded areas. However, certain species are parasitic rather than ectomycorrhizal. Members of the Gomphidiaceae family are thought to be parasitic on species of the Suillaceae family. These relationships are often highly specific. In other genera there are also parasitic species, such as Boletus parasiticus that grows on Scleroderma citrinum.

Edibility and identification

Boletos are often characterized by a spongy-looking surface under the cap, instead of the usual foils. This area can be of very varied colors, taking on reddish, whitish, yellowish, brownish or grayish tones. Many inedible boletos tend to present red or white in this porous area, so these shades are usually avoided when collecting this type of mushroom.

The genus Boletus also includes many edible species, some highly prized, such as Boletus edulis, Boletus aereus and Boletus pinophilus, as well as other species of lesser quality, such as Boletus badius. Boletus edulis and closely related species are of great commercial importance in Europe and North America. Species of the genus Suillus are often considered too viscous and tasteless an edible, however in Russia it is common for them to be collected and traded.

Many non-toxic boletos are very bitter, making them unfit for consumption.

The Paxillaceae family includes some poisonous species. Some members of the genus Boletus are also toxic, although they are rarely fatal. In this group, the species Boletus satanas and some related ones stand out.