''Exidia zelleri'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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

in the family

Auriculariaceae The Auriculariaceae are a family (biology), family of fungi in the order (biology), order Auriculariales. Species within the family were formerly referred to the "heterobasidiomycetes" or "jelly fungi", since many have gelatinous basidiocarps (fr ...

Basidiocarp In fungi, a basidiocarp, basidiome, or basidioma () is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do no ...

s (fruit bodies) are gelatinous, pale violaceous grey to grey-brown, button-shaped at first then coalescing and becoming irregularly effused. It grows on dead branches of broadleaved trees and is known from north-western North America.

Taxonomy

The species was first described in 1920 from Oregon by

mycologist Mycology is the branch of biology concerned with the study of fungi, including their taxonomy, genetics, biochemical properties, and use by humans. Fungi can be a source of tinder, food, traditional medicine, as well as entheogens, poison, and ...

Curtis Gates Lloyd Curtis Gates Lloyd (July 17, 1859 – November 11, 1926) was an American mycologist known for both his research on the gasteroid and polypore fungi, as well as his controversial views on naming conventions in taxonomy. He had a herbarium with ab ...

Description

The

basidiocarp In fungi, a basidiocarp, basidiome, or basidioma () is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do no ...

s of ''E. zelleri'' are gelatinous, button-shaped to top-shaped and attached to the wood at a point, sometimes coalescing to form effused, irregular masses up to 8 cm across. pale violaceous grey to grey brown, darkening with age. The surface is sparsely to densely covered in small papillae (pimples).

Microscopic characters

The translucent

hyphae A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one o ...

are thin-walled and form

clamp connections A clamp connection is a hook-like structure formed by growing hyphal cells of certain fungi. It is a characteristic feature of basidiomycete fungi. It is created to ensure that each cell, or segment of hypha separated by septa (cross walls), recei ...

Basidia A basidium (: basidia) is a microscopic spore-producing structure found on the hymenophore of reproductive bodies of basidiomycete fungi. The presence of basidia is one of the main characteristic features of the group. These bodies are also ...

are elliptical and consist of four longitudinally

septate In biology, a septum (Latin for ''something that encloses''; septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate. Examples Human anatomy * Interatrial se ...

cells.

Basidiospore 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 Ploidy () is the number of complete sets of chromos ...

s are allantoid (sausage shaped), 16 to 19 by 5 to 6

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

, with thin, smooth walls.

Similar species

Fruit bodies of ''

Exidia crenata ''Exidia crenata'' is a species of fungus in the family Auriculariaceae. It has the English name of amber jelly roll. Basidiocarps (fruit bodies) are gelatinous, brown to orange-brown, and turbinate (top-shaped). It typically grows on dead attach ...

'' and ''

Exidia recisa ''Exidia recisa'' is a species of fungus in the family Auriculariaceae. In the UK, it has the recommended English name of amber jelly. Basidiocarps (fruit bodies) are gelatinous, orange-brown, and turbinate (top-shaped). It typically grows on dea ...

'' also occur on broadleaved trees in North America, but are typically reddish to orange-brown and lack papillae on the surface. ''

Exidia glandulosa ''Exidia glandulosa'' is a species of fungus in the family Auriculariaceae. In the UK, it has the recommended English name of witch's butter. In North America it has variously been called black witches' butter, black jelly roll, or warty jelly fu ...

'' has papillae, but is typically blackish brown to black.

Distribution and habitat

''Exidia zelleri'' was originally described from Oregon and has also been recorded from California and British Columbia. It was originally collected on dead wood of ''

Sambucus ''Sambucus'' is a genus of between 20 and 30 species of flowering plants in the family Adoxaceae. The various species are commonly referred to as elder, with the flowers as elderflower, and the fruit as elderberry. Description Elders are mostl ...

'', but has subsequently been reported on other broadleaved trees.

References

{{Taxonbar, from=Q107674098 Auriculariales Fungi of North America Fungus species Taxa named by Curtis Gates Lloyd Fungi described in 1920