Echinodontiaceae
Encyclopedia
The Echinodontiaceae are a family
of fungi in the order Russulales
. Species of this family have a widespread distribution, although they are especially predominant in north temperate
zones. They are parasitic or saprobic on wood, and may cause white rots of angiosperms and gymnosperms.
to effused-reflexed basidiocarp
s, smooth to spiny hymenophore
s, amyloid
spores, dimitic hyphae, and cause white rot.
Molecular phylogenetic studies show that the Echinodontiaceae belong in the Russuloid clade
. Although some studies have suggested that the Echinodontium genus is closely related to the Amylostereum, a more recent study does not support this conclusion.
have a hydnaceous (with spinelike protuberances) hymenial
surface, dimitic hyphal system, smooth basidiospore
s, and in 3 of 4 species, a symbiotic association with horntail
s — Sirex and Urocerus species. The insects eat the fungus and help disperse the species by inoculating the wood of the host tree with either hyphal fragments or spores when they lay their eggs.
The genus Laurilia
has species characterized by an even to tuberculate hymenial surface, dimitic hyphal system, and echinulate
basidiospores.
In his monograph on the Echinodontiaceae, Gross (1964) suggested that Echinodontium
and Laurilia
were congeneric (sharing the same taxonomic genus), sharing features such as clamp connection
s, thick-walled encrusted cystidia and a brown context
. Later molecular data have supported this early hypothesis.
causes a destructive tree disease called "true heart rot
", meaning the decay is confined to the heartwood of the tree. The specific epithet tinctorium makes reference to the usage of fruit bodies (commonly known as the Indian Paint fungus) by Native Americans
to prepare red pigment
s. One of the pigment
s in this species, named echinotinctone (2,6-dihydroxy-1,8-dimethyl-3H-xanthen-3-one), is the first simple fluorone
pigment from fungi.
Another species, E. ballouii, known only from two collections on Atlantic white cedar, has not been found since 1909, coinciding with a reduction in the range of this tree due to harvesting.
Echinodontium ryvardenii is a species found only on Juniper
in Corsica
.
The illudane sesquiterpenoids echinolactones A and B have been isolated from the culture broth of E. japonicum. A number of triterpenoids have also been identified in E. tsugicola.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of fungi in the order Russulales
Russulales
The Russulales are an order of the Agaricomycetes,...
. Species of this family have a widespread distribution, although they are especially predominant in north temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
zones. They are parasitic or saprobic on wood, and may cause white rots of angiosperms and gymnosperms.
Description
Species of this family have resupinateResupination
Resupination generally means being upside-down, supine, facing upward. The word is derived from the Latin. In a biological context, the concept is commonly expressed with the adjectives "resupinate" or "non-resupinate."-Examples in green plants:...
to effused-reflexed basidiocarp
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 not produce such structures...
s, smooth to spiny hymenophore
Hymenophore
A hymenophore refers to the hymenium-bearing structure of a fungal fruiting body. Hymenophores can be smooth surfaces, lamellae, folds, tubes, or teeth....
s, amyloid
Amyloid
Amyloids are insoluble fibrous protein aggregates sharing specific structural traits. Abnormal accumulation of amyloid in organs may lead to amyloidosis, and may play a role in various neurodegenerative diseases.-Definition:...
spores, dimitic hyphae, and cause white rot.
Classification
The family was circumscribed by Donk in 1961, and monographed by Gross in 1964. He recognized six species in the genus Echinodontium (E. tinctorium, E. tsugicola, E. ballouii, E. japonicum, E. taxodii and E. sulcatum) with hymenia ranging from smooth to spiny. Jülich added another genus Laurilia (incorporating E. taxodii and E. sulcatum) when he described the family.Molecular phylogenetic studies show that the Echinodontiaceae belong in the Russuloid clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
. Although some studies have suggested that the Echinodontium genus is closely related to the Amylostereum, a more recent study does not support this conclusion.
Genera
Species in the genus EchinodontiumEchinodontium
Echinodontium is a genus of fungi in the family Echinodontiaceae.-Species:*Echinodontium ballouii H.L. Gross *Echinodontium japonicum Imazeki *Echinodontium ryvardenii Bernicchia & Piga...
have a hydnaceous (with spinelike protuberances) hymenial
Hymenium
The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some cells develop into sterile cells called cystidia or...
surface, dimitic hyphal system, smooth basidiospore
Basidiospore
A basidiospore is a reproductive spore produced by Basidiomycete fungi. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are produced by specialized fungal cells called basidia. In grills under a cap of one common species in the phylum of...
s, and in 3 of 4 species, a symbiotic association with horntail
Horntail
Horntail or wood wasp is the common name for any of the 100 non-social species of the family Siricidae, of the order Hymenoptera, a type of xylophagous sawfly...
s — Sirex and Urocerus species. The insects eat the fungus and help disperse the species by inoculating the wood of the host tree with either hyphal fragments or spores when they lay their eggs.
The genus Laurilia
Laurilia
Laurilia is a genus of fungi in the family Echinodontiaceae.-Species:*Laurilia sulcata Pouzar *Laurilia taxodii Pouzar...
has species characterized by an even to tuberculate hymenial surface, dimitic hyphal system, and echinulate
Echinulate
Echinulate is an adjective describing the spiny, or "spiky" nature of some spores found in plants and fungi; an example is the auxiliary cell. The words derives from the same root as the prefix echino, meaning that the shape is similar to the porcupine ....
basidiospores.
In his monograph on the Echinodontiaceae, Gross (1964) suggested that Echinodontium
Echinodontium
Echinodontium is a genus of fungi in the family Echinodontiaceae.-Species:*Echinodontium ballouii H.L. Gross *Echinodontium japonicum Imazeki *Echinodontium ryvardenii Bernicchia & Piga...
and Laurilia
Laurilia
Laurilia is a genus of fungi in the family Echinodontiaceae.-Species:*Laurilia sulcata Pouzar *Laurilia taxodii Pouzar...
were congeneric (sharing the same taxonomic genus), sharing features such as clamp connection
Clamp connection
A clamp connection is a structure formed by growing hyphal cells of certain fungi. It is created to ensure each septum, or segment of hypha separated by crossed walls, receives a set of differing nuclei, which are obtained through mating of hyphae of differing sexual types...
s, thick-walled encrusted cystidia and a brown context
Trama (mycology)
In mycology trama is a term for the inner, fleshy portion of a mushroom's basidiocarp, or fruit body. It is distinct from the outer layer of tissue, known as the pileipellis or cuticle, and from the spore-bearing tissue layer known as the hymenium....
. Later molecular data have supported this early hypothesis.
Notable species
The species Echinodontium tinctoriumEchinodontium tinctorium
Echinodontium tinctorium is a plant pathogen. It is commonly known as the Indian paint fungus.Some Plateau Indian tribes applied it to skin to prevent it from chapping.-External links:*...
causes a destructive tree disease called "true heart rot
Heart rot
thumb|300px|right|The bracket fungus [[Fistulina hepatica]] is one of many that cause heart rot.In trees, heart rot is a fungal disease that causes the decay of wood at the center of the trunk and branches. Fungi enter the tree through wounds in the bark and decay the heartwood. The diseased...
", meaning the decay is confined to the heartwood of the tree. The specific epithet tinctorium makes reference to the usage of fruit bodies (commonly known as the Indian Paint fungus) by Native Americans
Indigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
to prepare red pigment
Pigment
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...
s. One of the pigment
Pigment
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...
s in this species, named echinotinctone (2,6-dihydroxy-1,8-dimethyl-3H-xanthen-3-one), is the first simple fluorone
Fluorone
Fluorone is a heterocyclic chemical compound. It forms the core structure for various chemicals, most notably fluorone dyes, including erythrosine. It is an isomer of xanthone, sometimes referred to as an isoxanthone....
pigment from fungi.
Another species, E. ballouii, known only from two collections on Atlantic white cedar, has not been found since 1909, coinciding with a reduction in the range of this tree due to harvesting.
Echinodontium ryvardenii is a species found only on Juniper
Juniper
Junipers are coniferous plants in the genus Juniperus of the cypress family Cupressaceae. Depending on taxonomic viewpoint, there are between 50-67 species of juniper, widely distributed throughout the northern hemisphere, from the Arctic, south to tropical Africa in the Old World, and to the...
in Corsica
Corsica
Corsica is an island in the Mediterranean Sea. It is located west of Italy, southeast of the French mainland, and north of the island of Sardinia....
.
The illudane sesquiterpenoids echinolactones A and B have been isolated from the culture broth of E. japonicum. A number of triterpenoids have also been identified in E. tsugicola.