''Tremella iduensis'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Tremellaceae The Tremellaceae are a family of fungi in the order Tremellales. The family is cosmopolitan and contains both teleomorphic and anamorphic species, most of the latter being yeasts. All teleomorphs in the Tremellaceae are parasites of other fungi, ...

. It produces yellow, cornute-

frondose Frondosity (from Latin ''frondōsus'' meaning 'leafy') is the property of an organism that normally flourishes with fronds or leaf-like structures. Many frondose organisms are thalloid and lack the organization of tissues into organs, with the ...

, gelatinous

basidiocarps In fungi, a basidiocarp, basidiome, or basidioma () is the sporocarp (fungi), sporocarp of a basidiomycota, basidiomycete, the Multicellular organism, multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are chara ...

(fruit bodies) and is

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

on other fungi, probably species of ''

Hypoxylon ''Hypoxylon'' is a genus of ascomycetes commonly found on dead wood, and usually one of the earliest species to colonise dead wood. A common European species is ''Hypoxylon fragiforme'' which is particular common on dead trunks of beech. Based o ...

'' on dead attached and recently fallen branches of

broad-leaved trees A broad-leaved, broad-leaf, or broadleaf tree is any tree within the diverse botanical group of angiosperms that has flat leaves and produces seeds inside of fruits. It is one of two general types of trees, the other being a conifer, a tree with ne ...

. It has been recorded from Japan and China. ''Tremella flava'', described from Taiwan, may be a synonym.

Taxonomy

''Tremella iduensis'' was first published in 1939 by Japanese

mycologist Mycology is the branch of biology concerned with the study of fungus, fungi, including their genetics, genetic and biochemistry, biochemical properties, their Taxonomy (biology), taxonomy and ethnomycology, their use to humans, including as a so ...

Yosio Kobayasi.

Description

Fruit bodies are gelatinous, bright yellow, up to 2.5 cm (1 in) across, and branched, with cornute (horn-like) fronds. Microscopically, the

basidia A basidium () is a microscopic sporangium (a spore-producing structure) found on the hymenophore of fruiting bodies of basidiomycete fungi which are also called tertiary mycelium, developed from secondary mycelium. Tertiary mycelium is highly-c ...

are tremelloid (ellipsoid, with oblique to vertical septa), 4-celled, 17 to 18 by 12 to 13

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

. The

basidiospores A basidiospore is a reproductive spore produced by Basidiomycete fungi, a grouping that includes mushrooms, shelf fungi, rusts, and smuts. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are pro ...

are ovoid to ellipsoid, smooth, 8.5 to 9.5 by 7.5 to 8.5 μm.

Similar species

''Tremella flava'' was described from Taiwan as "resembling ''T. iduensis''" but differing in the size of its basidiospores (7 to 9 by 5 to 6.5 μm) and basidia. It has been suggested it may be a later synonym of ''T. iduensis''. Other yellow ''Tremella'' species are lobed or foliaceous and lack horn-like fronds.

Habitat and distribution

''Tremella iduensis'' is a parasite on lignicolous fungi, probably species of ''Hypoxylon''. It was originally described from ''

Castanopsis sieboldii ''Castanopsis sieboldii'', also known as the Itajii chinkapin or Itajii, is a species of evergreen tree that lives in subtropical eastern Asia. This is a climax species that is commonly found in the Japanese temperate rainforest. Specimens are al ...

'' and is found on dead, attached or recently fallen branches of broad-leaved trees. The species is currently known from Japan and China.

References

{{Taxonbar, from=Q18383438 Tremellomycetes Fungi described in 1939 Fungi of Asia