Also included in the Heterobasidiomycetes group are the various rust fungi and smut fungi.
The Tremellales and fungi of related orders are members of the division known as the heterobasidiomycetes, a small group of fungi with jelly-like texture. The Yellow Brain Fungus is perhaps the best known species in this group.
The characters that define the heterobasidiomycetes are microscopic and relate to the physical structure of the basidium, where the spores are formed. There are also several jelly-like fungi among the homobasidiomycetes (the division also containing the familiar cap-and-stem mushrooms and toadstools) - for example Bulgaria inquinans. We should not assume, therefore, that all gelatinous fungi are Heterobasidiomycetes.
Included in the heterobasidiomycetes are several orders of rather gelatinous fungi, some club shaped, others coral-like in structure and a further set forming amorphous blobs. The heterobasidiomycetes are characterised by the nature of the cells on which the spores develop; they are either septate (partitioned internally) or split into long prongs. Such details can only be investigated microscopically, of course, but in practice many of the so-called Jelly Fungi are quite distinctive and easy to identify in the field from macroscopic features.
The Tremellales is a small order of jelly-like fungi in a range of colours including white, yellow, orange brown and black. One of the most common fungi in this group is Tremella mesenterica (Yellow Brain Fungus). Some 140 European species from within this order have so far been identified and described.
The order Auriculariales comprises some 50 European species in a single family, the Auriculariaceae. The name comes from their family characteristic of being lobed rather like an ear. Apart from Auricularia auricula-judae (Jelly Ear) very few members of the Auriculariaceae are commonly encountered in the UK.
For more information about Jelly Fungi and a deeper insight into the ecology and structure of the species featured in our Heterobasidiomycetes Gallery pages, please see Pat O'Reilly's latest book Fascinated by Fungi, author-signed copies of which are available online here...