Heterobasidiomycetes - rusts and smuts
Homobasidiomycetes - mushrooms
Basidiomycota is a division of fungi that produce spores in a structure called a basidium, which often produces four basidiospores. They are traditionally divided into Homobasidiomycetes, which includes the true mushrooms (agarics, boletes), puffballs, toadstools and Heterobasidiomycetes such as rusts and smuts.
Some important orderss of homobasidiomycete mushrooms are:gasteromycete orders.
Basidiomycetes have a peculiar sexuality. They most often are heterothallic, but with a bipolar (unifactorial) or tetrapolar (bifactorial) mating system acting like many sexes. Usually, somatogamy (hyphogamy) is performed.
Most basidiomycetes live out most of their life as dikaryotic (heterokaryotic) mycelium, with karyogamy and meiosis happening in the basidium. There are examples of diploid life cycles as well: the genus Xerula was found to sometimes produce diploid clones as spores, and Armillaria, a common forest pathogen, has diploid mycelium, where karyogamy directly follows plasmogamy.
Asexual spores (conidia) are more and more being discovered also in the basidiomycetes.