''Sebacina'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

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

in the family Sebacinaceae. Its species are

mycorrhizal A mycorrhiza (from Greek μύκης ', "fungus", and ῥίζα ', "root"; pl. mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plan ...

, forming a range of associations with trees and other plants.

Basidiocarps 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 not ...

(fruit bodies) are produced on soil and litter, sometimes partly encrusting stems of living plants. The fruit bodies are cartilaginous to rubbery-gelatinous and variously effused (

corticioid The corticioid fungi are a group of fungi in the Basidiomycota typically having effused, smooth basidiocarps (fruit bodies) that are formed on the undersides of dead tree trunks or branches. They are sometimes colloquially called crust fungi or p ...

) to coral-shaped ( clavarioid). The genus has a cosmopolitan distribution.

Taxonomy

History

The genus was first published in 1871 by Louis and Charles Tulasne who had discovered that two species (''Sebacina incrustans'' and ''Sebacina epigaea'') previously referred to '' Corticium'' or '' Thelephora'' possessed septate

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- ...

, similar to those found in the genus '' Tremella''. Although it was unusual at that time to separate fungal genera on purely microscopic characters, ''Sebacina'' was erected for effused, ''Corticium''-like fungi with tremelloid basidia. Subsequent authors added many additional species of corticioid fungi with septate basidia to the genus. Most, however, proved unrelated to ''Sebacina''. In 1957 Ervin referred some ''Sebacina'' species to ''Heterochaetella'', '' Bourdotia'', and ''

Exidiopsis ''Exidiopsis'' is a genus of fungi in the family Auriculariaceae. The genus has a widespread distribution and contains around 30 species. One species, ''Exidiopsis effusa'', is responsible for the formation of hair ice on dead wood. Species ...

''. In 1961,

Wells Wells most commonly refers to: * Wells, Somerset, a cathedral city in Somerset, England * Well, an excavation or structure created in the ground * Wells (name) Wells may also refer to: Places Canada * Wells, British Columbia England * Wel ...

transferred all ''Sebacina'' species having

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

s on their

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 or ...

to the genus ''Exidiopsis'', retaining ''Sebacina'' for the minority of species lacking clamp connections.

Current status

Molecular A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioch ...

research, based on

cladistic Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived ch ...

analysis of

DNA sequences A nucleic acid sequence is a succession of bases signified by a series of a set of five different letters that indicate the order of nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. By convention, sequences are usu ...

, has shown that ''Sebacina'' as previously understood includes the genus ''Tremellodendron'' (established for a group of species with coral-like basidiocarps), but does not include some species that are not closely related to the

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

. These latter species have been placed in the genera '' Helvellosebacina'' and '' Paulisebacina''.

Description

Fruit bodies are typically cartilaginous or rubbery-gelatinous. In effused species (those that spread out loosely or flat), they are formed on the soil surface or in leaf litter, often encrusting fallen twigs and debris, sometimes encrusting the stem bases of living plants. In the type species, irregular or coral-like outgrowths may also be produced. In some species, fruit bodies are entirely coral- or net-like. Spores are white in mass.

Microscopic characters

Fruit bodies are composed of

lacking

s in a gelatinous matrix. In several species the hyphal system is

dimitic 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 or ...

. The

spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, ...

-bearing surface is initially covered in a layer of weakly branched hyphidia below which the

are formed. The basidia are tremelloid (ellipsoid and vertically septate), giving rise to long, sinuous sterigmata or epibasidia on which 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 ...

are produced. These spores are typically ellipsoid to oblong.

Mycorrhizal associations

''Sebacina'' species were assumed to be saprotrophic until DNA analysis of mycorrhizal roots showed that they were

ectomycorrhizal An ectomycorrhiza (from Greek ἐκτός ', "outside", μύκης ', "fungus", and ῥίζα ', "root"; pl. ectomycorrhizas or ectomycorrhizae, abbreviated EcM) is a form of symbiotic relationship that occurs between a fungal symbiont, or mycob ...

plant associates.

References

External links

{{Taxonbar, from=Q7442323 Sebacinales Agaricomycetes genera