Dictyonema
Encyclopedia
Dictyonema is a large and diverse genus
of mainly tropical lichen
s in the family Hygrophoraceae
.
between an ascomycete
fungi and a photosynthetic green algae
. However, a small percentage of lichens (approximately 10%) are cyanolichens and contain a photosynthetic cyanobacteria instead of green algae, and an even smaller number (less than 1%) are basidiolichen
s and contain a basidiomycete
fungi instead of an ascomycete. Dictyonema is a symbiosis between a basidiomycete fungi and a scytonema
toid cyanobacteria, making it both a basidiolichen and a cyanolichen, which is a very rare combination. This makes Dictyonema more closely related to mushroom
s than it is to most other lichens.
and Carl Kunth
after examining a novel fungus that was sent to them from Brazil. The genus was redefined in 1978 when Erast Parmasto
assessed 40 different species of basidiolichens that were previously divided into 3 families and 8 genera (including Cora, Dichonema, Laudatea, Rhipidonema, and Thelephora), and reduced them to 5 species in the single genus Dictyonema. This resulted in a rather diverse group of lichens that has since grown in size to more than 20 species, making Dictyonema the largest genus of basidiolichen. There is, however, some recent debate over whether or not all of these species should be included in the same genus.
, and filamentous. Most species grow on a soil, rock, moss, or rotting logs, but one species grows on the leaves of trees
. Although species of Dictyonema are mainly tropical, they range from the tropical lowlands to an elevation of 4300 m in the Andes.
, so it discovered lichen
ization independently from the ascomycete
lichens. Within the basidiomycetes, Dictyonema is closely related to three other genera of basidiolichens that are also in the family Hygrophoraceae
: Lichenomphalia
, Acantholichen
, and Cyphellostereum
. Interestingly, molecular data indicates that lichenization has evolved independently at least twice, and perhaps three times, within these four genera, which suggests that for some reason the fungi in Hygrophoraceae are predisposed to evolve into lichens. The majority of the other, non-lichenized fungi in this family are saprotrophic
(consuming decaying organic matter) or ectomycorrhizal (symbiotic with plant roots), although numerous species, such as Arrhenia
, grow on mosses and derive nutrition from them. It is not yet understood why these fungi are more inclined to become lichens.
of Amazon jungle of Ecuador. An infusion is made with this lichen that causes intense hallucinations, and it is used by the shaman to call upon malevolent spirits to curse people. It is also used to cause sterility.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of mainly tropical lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
s in the family Hygrophoraceae
Hygrophoraceae
The Hygrophoraceae are a family of fungi in the order Agaricales. Originally conceived as containing white-spored, thick-gilled agarics , including Hygrophorus and Hygrocybe species , DNA evidence has extended the limits of the family, so that it now contains not only agarics but also...
.
The Dictyonema symbiosis
Most lichens are a symbiosisSymbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...
between an ascomycete
Ascomycota
The Ascomycota are a Division/Phylum of the kingdom Fungi, and subkingdom Dikarya. Its members are commonly known as the Sac fungi. They are the largest phylum of Fungi, with over 64,000 species...
fungi and a photosynthetic green algae
Green algae
The green algae are the large group of algae from which the embryophytes emerged. As such, they form a paraphyletic group, although the group including both green algae and embryophytes is monophyletic...
. However, a small percentage of lichens (approximately 10%) are cyanolichens and contain a photosynthetic cyanobacteria instead of green algae, and an even smaller number (less than 1%) are basidiolichen
Basidiolichen
Basidiolichens are lichenized members of the Basidiomycota, a much smaller group of lichens than the far more common ascolichens in the Ascomycota. In arctic, alpine, and temperate forests, the most common basidiolichens are in the agaric genus Lichenomphalia and the clavarioid genus Multiclavula...
s and contain a basidiomycete
Basidiomycota
Basidiomycota is one of two large phyla that, together with the Ascomycota, comprise the subkingdom Dikarya within the Kingdom Fungi...
fungi instead of an ascomycete. Dictyonema is a symbiosis between a basidiomycete fungi and a scytonema
Scytonema
Scytonema is a genus of photosynthetic cyanobacteria that contains over 100 species. It grows in filaments that form dark mats. Many species are aquatic and are either free-floating or grow attached to a submerged substrate, while others species grow on terrestrial rocks, wood, soil, or plants...
toid cyanobacteria, making it both a basidiolichen and a cyanolichen, which is a very rare combination. This makes Dictyonema more closely related to mushroom
Mushroom
A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus; hence the word "mushroom" is most often applied to those fungi that...
s than it is to most other lichens.
Taxonomy and naming
The genus Dictyonema was first named in 1822 by Carl AdgardhCarl Adolph Agardh
Carl Adolph Agardh was a Swedish botanist specializing in algae, who was eventually appointed bishop of Karlstad.-Biography:...
and Carl Kunth
Carl Sigismund Kunth
Carl Sigismund Kunth , also Karl Sigismund Kunth or anglicized as Charles Sigismund Kunth, was a German botanist...
after examining a novel fungus that was sent to them from Brazil. The genus was redefined in 1978 when Erast Parmasto
Erast Parmasto
Erast Parmasto is a noted Estonian mycologist, bioscientist and botanist . He became a member of the Estonian Institute of Zoology and Botany in 1950 and served as its director from 1985-1990...
assessed 40 different species of basidiolichens that were previously divided into 3 families and 8 genera (including Cora, Dichonema, Laudatea, Rhipidonema, and Thelephora), and reduced them to 5 species in the single genus Dictyonema. This resulted in a rather diverse group of lichens that has since grown in size to more than 20 species, making Dictyonema the largest genus of basidiolichen. There is, however, some recent debate over whether or not all of these species should be included in the same genus.
Morphology and ecology
Dictyonema is a diverse group of lichens. There are species of a variety of different shapes, including foliose, crustoseCrustose
Crustose is a habit of some types of algae in which the plant grows tightly appressed to a substrate forming a biological layer of the adhering organism...
, and filamentous. Most species grow on a soil, rock, moss, or rotting logs, but one species grows on the leaves of trees
Foliicolous
Foliicolous refers to the growth habit of certain lichens, algae, and fungi that prefer to grow on the leaves of vascular plants. There have been about 700 species of foliicolous lichens identified, most of which are found in the tropics.-External links:*...
. Although species of Dictyonema are mainly tropical, they range from the tropical lowlands to an elevation of 4300 m in the Andes.
Evolutionary relationships and lichenization
The Dictyonema fungus is a basidiomyceteBasidiomycota
Basidiomycota is one of two large phyla that, together with the Ascomycota, comprise the subkingdom Dikarya within the Kingdom Fungi...
, so it discovered lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
ization independently from the ascomycete
Ascomycota
The Ascomycota are a Division/Phylum of the kingdom Fungi, and subkingdom Dikarya. Its members are commonly known as the Sac fungi. They are the largest phylum of Fungi, with over 64,000 species...
lichens. Within the basidiomycetes, Dictyonema is closely related to three other genera of basidiolichens that are also in the family Hygrophoraceae
Hygrophoraceae
The Hygrophoraceae are a family of fungi in the order Agaricales. Originally conceived as containing white-spored, thick-gilled agarics , including Hygrophorus and Hygrocybe species , DNA evidence has extended the limits of the family, so that it now contains not only agarics but also...
: Lichenomphalia
Lichenomphalia
Lichenomphalia is both a basidiolichen and an agaric genus. Most of the species have inconspicuous lichenized thalli that consist of scattered, small, loose, nearly microscopic green balls or foliose small flakes containing single-celled green algae in the genus Coccomyxa, all interconnected by a...
, Acantholichen
Acantholichen
Acantholichen is a lichenized genus of fungi in the family Corticiaceae. It is a monotypic genus, containing the sole species Acantholichen pannariodes, discovered originally in Costa Rica in 1998. This species has a bluish, gelatinous thallus, and a fine, white powdery bloom covering the hairy...
, and Cyphellostereum
Cyphellostereum
Cyphellostereum is genus of basidiolichens. Species produce white, somewhat cup-shaped fruit bodies on a thin film of green on soil which is the thallus...
. Interestingly, molecular data indicates that lichenization has evolved independently at least twice, and perhaps three times, within these four genera, which suggests that for some reason the fungi in Hygrophoraceae are predisposed to evolve into lichens. The majority of the other, non-lichenized fungi in this family are saprotrophic
Detritivore
Detritivores, also known as detritophages or detritus feeders or detritus eaters or saprophages, are heterotrophs that obtain nutrients by consuming detritus . By doing so, they contribute to decomposition and the nutrient cycles...
(consuming decaying organic matter) or ectomycorrhizal (symbiotic with plant roots), although numerous species, such as Arrhenia
Arrhenia
Arrhenia is a genus of about 25 species in the Tricholomataceae family. Arrhenia also includes species formerly placed in the genera Leptoglossum and Phaeotellus and the lectotype species itself has an unusual growth form that would not normally be called agaricoid...
, grow on mosses and derive nutrition from them. It is not yet understood why these fungi are more inclined to become lichens.
Traditional use by people
An unidentified species of Dictyonema, possibly Dictyonema sericeum, is called nenendape by the HuaoraniHuaorani
The Huaorani, Waorani or Waodani, also known as the Waos, are native Amerindians from the Amazonian Region of Ecuador who have marked differences from other ethnic groups from Ecuador. The alternate name Auca is a pejorative exonym used by the neighboring Quechua Indians, and commonly adopted by...
of Amazon jungle of Ecuador. An infusion is made with this lichen that causes intense hallucinations, and it is used by the shaman to call upon malevolent spirits to curse people. It is also used to cause sterility.
External links
- Picture of Dictyonema glabratum at TicoLichen
- Picture of Dictyonema sericeum at TicoLichen
- Dictyonema at Index FungorumIndex FungorumIndex Fungorum, an international project to index all formal names in the Fungi Kingdom. Somewhat comparable to the IPNI, but with more contributing institutions....