thumb|Heterobasidiomycetes found in a nature reserve near [[Comboyne, New South Wales, Australia]]
Heterobasidiomycetes, including jelly fungi, smuts and rusts, are basidiomycetes with septate basidia. This contrasts them to homobasidiomycetes (alternatively called holobasidiomycetes), including most mushrooms and other Agaricomycetes, which have aseptate basidia. The division of all basidiomycetes between these two groups has been influential in fungal taxonomy, and is still used informally, but it is no longer the basis of formal classification. In modern taxonomy homobasidiomycetes roughly correspond to the monophyletic class Agaricomycetes, whereas heterobasidiomycetes are paraphyletic and as such correspond to various taxa from different taxonomic ranks, including the Basidiomycota other than Agaricomycetes and a few basal groups within Agaricomycetes.
Distinction between homo- and heterobasidiomycetes
In addition to having septate basidia, heterobasidiomycetes also frequently possess large irregularly shaped sterigmata and spores that are capable of self-replication – a process where a spore, instead of germinating into a vegetative hypha, gives rise to a sterigma and a new spore, which is then discharged as if from a normal basidium. In contrast, homobasidiomycetes, in addition to having aseptate basidia, generally have small regularly shaped sterigmata and spores that do not self-replicate. In different classifications, different features have been stressed. He divided all basidiomycetes between these two groups. This distinction formed the basis of various classifications up to the end of the 20th century. !! Talbot 1968 !! Donk 1972 !! Wells 1994
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Protobasidiomycetes <small>(septate basidia)</small>
:Auricularieae
:Tremellineae
:Uredineae <small>(=Pucciniales)</small>
:Ustilagineae
Autobasidiomycetes <small>(aseptate basidia)</small>
:containing only homobasidiomycetes sensu stricto
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Hétérobasidiés
<small>(self-replicating spores, septate basidia)</small>
:Auriculariaceae
:Caloceraceae <small>(=Dacrymycetaceae)</small>
:Tremellaceae
:Tulasnellaceae
Homobasidiés
<small>(spores not self-replicating, basidia aseptate)</small>
:containing only homobasidiomycetes sensu stricto
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Heterobasidiomycetidae
<small>(completely septate basidia)</small>
:Ustilaginales
:Uredinales <small>(=Pucciniales)</small>
:Eutremellales <small>(including Auriculariaceae and Tremellaceae)</small>
Metabasidiomycetidae
<small>(incompletely septate or aseptate basidia, large swollen sterigmata, self-replicating spores)</small>
:Metatremellales <small>(including Ceratobasidiaceae, Dacrymycetaceae and Tulasnellaceae)</small>
Homobasidiomycetidae
<small>(completely aseptate basidia, sterigmata not swollen, spores not self-replicating)</small>
:containing only homobasidiomycetes sensu stricto
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Teliobasidiomycetes
<small>(meiotically septate basidia, teliospores)</small>
:smuts
:rusts
Phragmobasidiomycetes
<small>(meiotically septate basidia, no teliospores)</small>
:auricularioid fungi
:tremelloid fungi
Holobasidiomycetes
<small>(basidia not meiotically septate; identical to Donk 1972)</small>
:containing ceratobasidioid, dacrymycetoid and tulasnelloid fungi in addition to homobasidiomycetes sensu stricto
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Hemibasidiomycetes
<small>(meiotically septate basidia)</small>
:smuts
Phragmobasidiomycetes
<small>(meiotically septate basidia)</small>
:rusts
:auricularioid fungi
:tremelloid fungi
Holobasidiomycetes
<small>(basidia not meiotically septate; identical to Talbot 1968)</small>
:containing ceratobasidioid, dacrymycetoid and tulasnelloid fungi in addition to homobasidiomycetes sensu stricto
||
Teliomycotina
<small>(septal pore simple)</small>
:smuts
:rusts
Basidiomycotina
<small>(septal pore complex)</small>
:Heterobasidiomycetes
:<small>(basidia septate or if not septate then deeply divided, spores self-replicating)</small>
::Heterobasidiomycetidae
:::Auriculariales
:::Ceratobasidiales
:::Dacrymycetales
:::Tulasnellales
::Tremellomycetidae
:::Tremellales
:Homobasidiomycetes
:<small>(basidia aseptate, spores not self-replicating)</small>
::containing only homobasidiomycetes sensu stricto
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Modern view
A phylogenetic analysis of nuclear ribosomal genes in 1993