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''Sebacina'' is a
genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
fungi 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 ...
in the family
Sebacinaceae The Sebacinaceae are a family of fungi in the order Sebacinales. Species produce basidiocarps (fruit bodies} that are gelatinous or cartilaginous and variously corticioid, clavarioid, bracket-like, or jelly-like. Microscopically, all have septa ...
. 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 (fungi), sporocarp of a basidiomycota, basidiomycete, the Multicellular organism, multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are chara ...
(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 pa ...
) to coral-shaped ( clavarioid). The genus has a
cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...
.


Taxonomy


History

The genus was first published in 1871 by
Louis Louis may refer to: * Louis (coin) * Louis (given name), origin and several individuals with this name * Louis (surname) * Louis (singer), Serbian singer * HMS ''Louis'', two ships of the Royal Navy See also Derived or associated terms * Lewis ( ...
and
Charles Tulasne Charles Tulasne (5 September 1816 – 28 August 1884) was a French physician, mycologist and illustrator born in Langeais in the département of Indre-et-Loire. He received his medical doctorate in 1840 and practiced medicine in Paris until 18 ...
who had discovered that two species (''Sebacina incrustans'' and ''Sebacina epigaea'') previously referred to '' Corticium'' or ''
Thelephora ''Thelephora'' is a genus of fungi in the family Thelephoraceae. The genus has a widespread distribution and contains about 50 species. Fruit bodies of species are leathery, usually brownish at maturity, and range in shape from coral-like tufts t ...
'' possessed
septate In biology, a septum (Latin for ''something that encloses''; plural 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 * Interatr ...
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 ...
, similar to those found in the genus ''
Tremella ''Tremella'' is a genus of fungi in the family Tremellaceae. All ''Tremella'' species are parasites of other fungi and most produce anamorphic yeast states. Basidiocarps (fruit bodies), when produced, are gelatinous and are colloquially classed ...
''. 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 Hair ice, also known a ...
''. 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 * Wells ...
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 bioche ...
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 char ...
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 usua ...
, 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. 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
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 ...
lacking
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 in a gelatinous matrix. In several species the hyphal system is dimitic. 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, f ...
-bearing surface is initially covered in a layer of weakly branched hyphidia below which 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 formed. The basidia are tremelloid (ellipsoid and vertically septate), giving rise to long, sinuous
sterigmata In biology, a sterigma (pl. sterigmata) is a small supporting structure. It commonly refers to an extension of the basidium (the spore-bearing cells) consisting of a basal filamentous part and a slender projection which carries a spore at the ti ...
or epibasidia on which the basidiospores are produced. These spores are typically ellipsoid to oblong.


Mycorrhizal associations

''Sebacina'' species were assumed to be
saprotrophic Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ( ...
until DNA analysis of mycorrhizal roots showed that they were ectomycorrhizal plant associates.


References


External links

{{Taxonbar, from=Q7442323 Sebacinales Agaricomycetes genera