| Dictyonema | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Basidiomycota |
| Class: | Agaricomycetes |
| Order: | Agaricales |
| Family: | Hygrophoraceae |
| Genus: | Dictyonema C.Agardh ex Kunth (1822) |
| Type species | |
| Dictyonema excentricum C.Agardh (1822) | |
Dictyonema is a genus of mainly tropical basidiolichens in the family Hygrophoraceae. [1]
Most lichens are a symbiosis between an ascomycete fungus and a photosynthetic green alga. However, a small percentage of lichens (approximately 10%) are cyanolichens and contain a photosynthetic cyanobacterium instead of green algae, [2] and an even smaller number (less than 1%) are basidiolichens and contain a basidiomycete fungus instead of an ascomycete. [3] This makes Dictyonema more closely related to mushrooms than it is to most other lichens.
The genus Dictyonema was first named in 1822 by Carl Agardh and Carl Kunth after examining a novel fungus that was sent to them from Brazil. [4] 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. [5] This resulted in a rather diverse group of lichens that has since grown in size to more than 20 species. [3] There is, however, some recent debate over whether or not all of these species should be included in the same genus. [6]
As of October 2024 [update] , Species Fungorum (in the Catalogue of Life) accept 38 species in Dictyonema. [7]
Dictyonema is a diverse group of lichens. There are species of a variety of different shapes, including foliose, crustose, and filamentous. [3] Most species grow on soil, rock, [20] moss, [21] or rotting logs, [22] but one species grows on the leaves of trees. [3] Although species of Dictyonema are mainly tropical, they range from the tropical lowlands to an elevation of 4,300 m (14,100 ft) in the Andes. [20]
The Dictyonema fungus is a basidiomycete, so it developed lichenization independently from the ascomycete lichens. [23] Within the basidiomycetes, Dictyonema is closely related to three other genera of basidiolichens that are also in the family Hygrophoraceae: Lichenomphalia , Acantholichen , and Cyphellostereum . [3] The 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. [3] 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. [3] [24] It is not yet understood why these fungi are more inclined to become lichens. [3]
An unidentified species of Dictyonema is called nenendape by the Huaorani people of Amazon jungle of Ecuador. An infusion made with this lichen is said to cause intense hallucinations, and it is used by the shaman to call upon malevolent spirits to curse people. It is also used to cause sterility. [25]
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 it now contains not only agarics, but also basidiolichens and corticioid fungi. Species are thus diverse and are variously ectomycorrhizal, lichenized, associated with mosses, or saprotrophic. The family contains 34 genera and over 1000 species. None is of any great economic importance, though fruit bodies of some Hygrocybe and Hygrophorus species are considered edible and may be collected for sale in local markets.
Cyphellostereum is a genus of basidiolichens. Species produce white, somewhat cup-shaped fruit bodies on a thin film of green on soil which is the thallus. All Cyphellostereum species have nonamyloid spores and tissues, lack clamp connections, and also lack hymenial cystidia.
Acantholichen is a fungal genus in the family Hygrophoraceae. The genus was circumscribed by Norwegian lichenologist Per Magnus Jørgensen to contain the type, and at that time, only species, the basidiolichen Acantholichen pannarioides, discovered originally in Costa Rica in 1998. This species has a bluish, gelatinous thallus, and a fine, white powdery bloom covering the hairy upper surface; this surface is said to resemble "an unshaven chin". Five additional species, all basidiolichens, were added to the genus in 2016 following an in-depth analysis of specimens collected from the Galápagos, Costa Rica, Brazil and Colombia.
Dictyonema hernandezii is a species of basidiolichen in the family Hygrophoraceae. Found in montane rainforests of Costa Rica and in Colombia, it was described as new to science in 2011. The specific epithet hernandezii honours Venezuelan lichenologist Jesús Hernández.
Cora hirsuta is a species of basidiolichen in the family Hygrophoraceae. Found in the páramo region near Bogotá at over 3,000 m (9,800 ft) elevation, it was described as new to science in 2011. The lichen, characterised by its distinctively hairy upper surface and smaller lobes, thrives in a variety of habitats, including soil, bryophytes, and as epiphytes on trees.
Cora is a large genus of basidiolichens in the family Hygrophoraceae. Modern molecular phylogenetics research has revealed a rich biodiversity in this largely tropical genus.
Cora santacruzensis is a species of basidiolichen in the family Hygrophoraceae. Found in the Galapagos, it was formally described as a new species in 2016 by Manuela Dal Forno, Frank Bungartz, and Alba Yánez-Ayabaca. The specific epithet santacruzensis refers to Santa Cruz Island, the type locality where the lichen was first documented scientifically. Here it was found at an abandoned farm behind El Puntudo, where it was growing on a shaded branch of an avocado tree. A paratype specimen was collected from a Cinchona tree. The lichen is one of two presumably endemic Cora species found on the Galapagos; the other is Cora glabrata.
Cora arachnoidea is a species of basidiolichen in the family Hygrophoraceae. Found in Venezuela, it was formally described as a new species in 2013 by Jesús Hernández and Robert Lücking. The type specimen was collected in the surroundings of Laguna de Mucubají, at an altitude of 3,626 m (11,896 ft). The specific epithet makes reference to the arachnoid (cobwebby) texture of the thallus surface. Another member of the genus with a similar surface is Cora hirsuta.
Cora aspera is a species of basidiolichen in the family Hygrophoraceae. Found in Central and South America, it was formally described as a new species in 2013 by Karina Wilk, Robert Lücking, and Eduardo Morales. The type specimen was collected in the Siberia region near La Palma at an altitude of 2,582 m (8,471 ft). Here, in a Yungas cloud forest, it grows as an epiphyte on bark. The specific epithet alludes to the roughened texture of the thallus surface, especially under dry conditions. The lichen has been recorded from Costa Rica, Colombia, Ecuador, Bolivia, and Peru, and it grows on twigs and branches in montane rainforest and páramo vegetation.
Cora byssoidea is a species of basidiolichen in the family Hygrophoraceae. Found in Colombia, it was formally described as a new species in 2013 by lichenologists Robert Lücking and Bibiana Moncada. The type specimen was collected in Páramo El Verjón at an altitude of 3,200 m (10,500 ft). Here it was found growing as an epiphyte on twigs and small branches of páramo vegetation. The lichen is only known from the type locality. The specific epithet byssoidea refers to the byssoid surface of the upper thallus. This surface comprises an irregularly dissolved layer of single hyphae in the cortex. A lookalike species, Cora hirsuta, also found at the same location, has a similar surface texture. In this lichen the surface is made of erect trichomes of agglutinated hyphae; despite their similarities, the two species are not closely related.
Cora cyphellifera is a species of basidiolichen in the family Hygrophoraceae. Found in northern Ecuador, it was formally described as a new species in 2013 by Manuela Dal-Forno, Frank Bungartz, and Robert Lücking. The type specimen was collected near the entrance to the Alto Choco Reserve at an elevation of 2,053 m (6,736 ft). Here, in open, disturbed forest patches, the lichen grows as an epiphyte on tree branches and twigs, forming foliose, light bluish-green thalli up to 15 cm (6 in) across, and comprising 20 to 30 semicircular lobes in each thallus. Cora cyphellifera is only known to occur at the type locality, which is a montane rainforest. The specific epithet refers to the unusual cyphelloid structure of the thallus; this characteristic is otherwise unknown in the genus Cora. According to the authors, "it almost looks like the lichenized thallus is parasitized by a non-lichenized, cyphelloid mushroom".
Cora inversa is a species of basidiolichen in the family Hygrophoraceae. Found in Colombia, it was formally described as a new species in 2013 by lichenologists Robert Lücking and Bibiana Moncada. The type specimen was collected in the Páramo El Verjón at an altitude of 3,200 m (10,500 ft). Here the lichen grows as an epiphyte, typically at the base of páramo shrubs, and often between bryophytes. The specific epithet refers to the partially strigose underside, presenting in an inverse fashion compared to Cora hirsuta, which is strigose on the upper side.
Cora squamiformis is a species of basidiolichen in the family Hygrophoraceae. Found in the high Andes of South America, it was formally described as a new species in 2013 by Karina Wilk, Robert Lücking, and Alba Yánez-Ayabaca. The type specimen was collected in Madidi National Park at an altitude of 4,677 m (15,344 ft). The lichen occurs in Bolivia and Ecuador, where it grows on the ground between bryophytes amongst high-mountain vegetation. It forms olive-grey to grey thalli up to 3 cm (1.2 in) across, each typically comprising 3 to 5 semicircular lobes. The specific epithet squamiformis refers to the squamulose (scaley) appearance of the thallus. A close relative, Cora pavonia, occurs in the same habitat in Ecuador; it has much larger thalli and a different lobe configuration than C. squamiformis.
Cora strigosa is a species of basidiolichen in the family Hygrophoraceae. Found in Peru, it was formally described as a new species in 2013 by Robert Lücking, Elias Paz, and Luis Salcedo. The type specimen was collected in Piscacucho at an altitude of about 2,700 m (8,900 ft). Here, in montane rainforest and pasture near Machu Picchu, the lichen grows on rocks together with other lichens, such as Hypotrachyna and Rimelia. Cora strigosa is only known to occur at the type locality. The specific epithet strigosa refers to the strigose upper surface of the thallus, especially prominent where they project radially at the margins. This lichen resembles Cora hirsuta, but it is not closely related.
Acantholichen pannarioides is a species of basidiolichen in the family Hygrophoraceae, and the type species of genus Acantholichen. The lichen has a bluish-tinged, gelatinous thallus with a surface texture that has a powdery to hairy texture. It is found in montane regions of Central America and northern South America, where it grows on forest litter, bark, on bryophytes, and on other lichens.
Dictyonema barbatum is a species of basidiolichen in the family Hygrophoraceae. It is endemic to the Galápagos Islands, where it grows as an epiphyte on the bark of branches and trunks, often on introduced plants such as avocado and guava trees. It was formally described as a new species in 2017 by Manuela Dal-Forno, Frank Bungartz, and Robert Lücking. The type specimen was collected near the southern crater rim of the Sierra Negra, at an altitude of 1,055 m (3,461 ft). Its preferred habitat is open areas with lots of rainfall and light exposure. The lichen forms shelf-like, filamentous brackets comprising individual semicircular lobes up to 8 cm (3 in) wide. The specific epithet barbatum refers to the "beard-like" white hairs on the shelf margins, a characteristic feature of this species. These "hairs" are sheaths of fungal hyphae that lack photobiont filaments.
Dictyonema darwinianum is a species of basidiolichen in the family Hygrophoraceae. It is endemic to the Galápagos Islands, where it grows as an epiphyte on the bark of branches and trunks, often closely associated with or overgrowing bryophytes and interspersed detritus. It was formally described as a new species in 2017 by Manuela Dal-Forno, Frank Bungartz, and Robert Lücking. The type specimen was collected along the trail from Bellavista to El Puntudo on Santa Cruz Island at an altitude of 502 m (1,647 ft). The lichen is common and widespread on the Galápagos Islands, where it forms dark bluish-green filamentous and crust-like mats on Frullania liverworts and associated forest detritus. The specific epithet darwinianum honours Charles Darwin and the Charles Darwin Foundation.
Dictyonema subobscuratum is a species of basidiolichen in the family Hygrophoraceae. It is endemic to the Galápagos Islands, where it mostly grows as an epiphyte over bryophytes on branches and trunks in humid zones. It was formally described as a new species in 2017 by Manuela Dal-Forno, Frank Bungartz, and Robert Lücking. The type specimen was collected on Floreana Island along the rim trail to Cerro Pajas at an altitude of 442 m (1,450 ft); it has also been recorded from Santa Cruz Island. The lichen forms dark bluish-green filamentous, irregular mats that grow in patches up to 5 cm (2.0 in) across. The specific epithet subobscuratum refers to its similarity with Dictyonema obscuratum, found in Brazil.
Dictyonema aeruginosulum is a species of basidiolichen in the family Hygrophoraceae. Characteristics of the lichen include its distinctive finger-like projections and blue-green hue. It is distinguishable from its closest relatives by its unique morphology and the absence of clamp connections in its structure. Dictyonema aeruginosulum is an epiphyte, forming thick mats on tree trunks within rainforest regions. The species was first identified in Costa Rica's Tenorio Volcano National Park, and it has only been recorded from this location.
Dictyonema metallicum is a species of basidiolichen in the family Hygrophoraceae. It is found in the montane rainforests of Ecuador. Characterised by its metallic shimmer, it is an epiphytic lichen that spans large areas on host tree trunks and frequently extends to adjacent bryophytes. Its unique visual texture is created by the loosely interwoven dark blue fibrils of the thallus, a thin, compressed filamentous layer, accentuated by a silver prothallus.
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