Boletales

The Boletales are an order of homobasidiomycetes, containing a large number of species with a diverse array of fruiting body types. The boletes are the best known members of this group, and until recently, the Boletales were thought to only contain boletes. The Boletales are now known to contain distinct groups of agarics, gasteromycetes, and other fruiting body types.

Taxonomy
The order Boletales originally was erected to describe boletes, however, based on micromorphological and molecular phylogenetic characteristics, it has recently been established that a large number of non-bolete species belong to this group as well. The order also includes some gilled mushrooms, in the families Gomphidiaceae and Paxillaceae, which often have the same flesh texture as the Boletes, spore-bearing tissue which is also easily separable from the cap, and similar microscopic characteristics of spores and cystidia. Molecular phlyogenetic evidence has moved several other physically dissimilar groups into Boletales, including the Sclerodermataceae (earthballs) and the Rhizopogonaceae (false truffles).

New research shows the Sclerodermataceae, Boletinellaceae and Gyroporaceae appear to form a discrete group within the Boletales. Thus the boletes of Gyrodon and Phlebopus are more closely related to earthballs of Scleroderma than to Boletus. Similarly, the bolete genus Suillus is more closely related to the agarics and false truffles of Chroogomphus, Gomphidius, and Rhizopogon than to Boletus.

In some classification systems, a part of the family Boletaceae is separated off to form the family Strobilomycetaceae.

Ecology
The Boletales are largely ectomycorrhizal fungi, and hence are found mainly in or near woodlands. Certain species are parasitic rather than ectomycorrhizal. Members of the family Gomphidiaceae are thought to be parasitic upon members of the family Suillaceae; these relationships are often highly species-specific. Other parasitic boletes included Boletus parasiticus which grows on Scleroderma citrinum. .

Edibility
The genus Boletus contains many members which are edible and tasty, most notably, the Boletus edulis group, including Boletus aereus and Boletus pinophilus, though many others are eaten as well, such as Boletus badius. Boletus edulis and its relatives are of great commercial importance in Europe and North America. Species of Suillus are considered by many to be slimy and insipid, however, in Russia, they are often pickled and even sold commercially this way.

Many boletes, while non-toxic, are nonetheless bitter tasting and inedible.

The Paxillaceae contain a number of species that have been implicated in fatal poisonings. A few boletes are also highly toxic (though generally not deadly), notably the (fortunately fairly conspicious) Boletus satanas and allies. Still, many mushroom hunters recommend that beginners start with boletes, since deadly mix-ups are far less likely than with agarics.