''Dictyonema'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of mainly tropical

basidiolichen Basidiolichens are lichenized members of the Division (taxonomy), division Basidiomycota within the subkingdom Dikarya of the Kingdom (biology), kingdom Fungus, Fungi. They form a diverse yet much smaller group of lichens than the far more commo ...

s in the family

Hygrophoraceae The Hygrophoraceae are a family (biology), family of fungi in the order (biology), order Agaricales. Originally conceived as containing white-spored, thick-gilled agarics (gilled mushrooms), including ''Hygrophorus'' and ''Hygrocybe'' species (th ...

The ''Dictyonema'' symbiosis

Most lichens are a

symbiosis Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biological interaction, between two organisms of different species. The two organisms, termed symbionts, can fo ...

between an

ascomycete Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The def ...

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

and a photosynthetic

green alga The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( ...

. However, a small percentage of lichens (approximately 10%) are

cyanolichen Cyanolichens are lichens in which the fungal component () partners with cyanobacteria () for photosynthesis, rather than the green algae found in most other lichens. In some cyanolichens, known as forms, the cyanobacteria form an extensive throug ...

s and contain a photosynthetic

cyanobacterium Cyanobacteria ( ) are a group of autotrophic gram-negative bacteria that can obtain biological energy via oxygenic photosynthesis. The name "cyanobacteria" () refers to their bluish green (cyan) color, which forms the basis of cyanobacteria' ...

instead of green algae, and an even smaller number (less than 1%) are

s and contain a

basidiomycete Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basid ...

fungus instead of an ascomycete. This makes ''Dictyonema'' more closely related to

mushroom A mushroom or toadstool is the fleshy, spore-bearing Sporocarp (fungi), fruiting body of a fungus, typically produced above ground on soil or another food source. ''Toadstool'' generally refers to a poisonous mushroom. The standard for the n ...

s than it is to most other lichens.

Taxonomy and naming

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.Kunth, CS, and CA Agardh. 1822. Synopsis Plantarum, Quas in Itinere ad Plagam Aequinoctialem Orbis Novi, Collegerunt Al. de Humboldt et Am. Bonpland (Paris). Volume 1, pg. 1. The genus was redefined in 1978 when

Erast Parmasto Erast Parmasto (28 October 1928 – 24 April 2012) was a noted Estonian mycologist, bioscientist and botanist and onetime director of the Estonian Institute of Zoology and Botany. Parmasto was born in Nõmme. He became a member of the Estonian I ...

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. There is, however, some recent debate over whether or not all of these species should be included in the same genus.

Species

Species Fungorum ''Index Fungorum'' is an international project to index all formal names (Binomial nomenclature, scientific names) in the fungus Kingdom (biology), kingdom. As of 2015, the project is based at the Royal Botanic Gardens, Kew, one of three partn ...

(in the

Catalogue of Life The Catalogue of Life (CoL) is an online database that provides an index of known species of animals, plants, fungi, and microorganisms. It was created in 2001 as a partnership between the global Species 2000 and the American Integrated Taxono ...

) accept 38 species in ''Dictyonema''. *'' Dictyonema aeruginosulum'' *'' Dictyonema album'' – Africa *'' Dictyonema andinum'' *'' Dictyonema applanatum'' – Bolivia *'' Dictyonema barbatum'' –

Galápagos Islands The Galápagos Islands () are an archipelago of volcanic islands in the Eastern Pacific, located around the equator, west of the mainland of South America. They form the Galápagos Province of the Republic of Ecuador, with a population of sli ...

*'' Dictyonema caespitosum'' *'' Dictyonema coppinsii'' – Europe *'' Dictyonema darwinianum'' – Galápagos Islands *'' Dictyonema diducens'' *'' Dictyonema discocarpum'' – Bolivia *'' Dictyonema duidense'' *'' Dictyonema giganteum'' – Colombia *'' Dictyonema gomezianum'' *'' Dictyonema guadalupense'' *'' Dictyonema hapteriferum'' – Bolivia *'' Dictyonema hernandezii'' *'' Dictyonema huaorani'' *'' Dictyonema irpicinum'' *'' Dictyonema irrigatum'' *'' Dictyonema krogiae'' – Africa *'' Dictyonema laurae'' *'' Dictyonema lawreyi'' *'' Dictyonema ligulatum'' *'' Dictyonema metallicum'' *'' Dictyonema moorei'' *'' Dictyonema obscuratum'' *'' Dictyonema pectinatum'' – Galápagos Islands *'' Dictyonema phyllophilum'' *'' Dictyonema ramificans'' – Galápagos Islands *'' Dictyonema reticulatum'' *'' Dictyonema scabridum'' *'' Dictyonema subinvolutum'' *'' Dictyonema subobscuratum'' – Galápagos Islands *'' Dictyonema subsericeum'' *'' Dictyonema thelephora'' *'' Dictyonema tricolor'' – Africa *'' Dictyonema umbricola'' *'' Dictyonema yunnanum'' – China

Morphology and ecology

''Dictyonema'' is a diverse group of lichens. There are species of a variety of different shapes, including

foliose A foliose lichen is a lichen with flat, leaf-like , which are generally not firmly bonded to the substrate on which it grows. It is one of the three most common lichen growth forms, growth forms of lichens. It typically has distinct upper and lo ...

crustose Crustose is a Habit (biology), habit of some types of algae and lichens in which the organism grows tightly appressed to a substrate, forming a biological layer. ''Crustose'' adheres very closely to the Substrate (biology), substrates at all poin ...

, and

filamentous The word filament, which is descended from Latin ''filum'' meaning "Thread (yarn), thread", is used in English for a variety of thread-like structures, including: Astronomy * Galaxy filament, the largest known cosmic structures in the universe * ...

. Most species grow on 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 in the Andes.

Evolutionary relationships and lichenization

The ''Dictyonema'' fungus is a

, so it developed

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

ization independently from the

lichens. Within the basidiomycetes, ''Dictyonema'' is closely related to three other genera of basidiolichens that are also in the family

: ''

Lichenomphalia ''Lichenomphalia'' is both a basidiolichen and an agaric genus. Most of the species have inconspicuous lichenized thallus, thalli that consist of scattered, small, loose, nearly microscopic green balls or foliose small flakes containing single-ce ...

'', '' Acantholichen'', and '' Cyphellostereum''. The

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

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 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 ...

(consuming decaying organic matter) or

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

(symbiotic with plant roots), although numerous species, such as ''

Arrhenia ''Arrhenia'' is a genus of fungi in the family Hygrophoraceae. ''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 normal ...

'', grow on mosses and derive nutrition from them. It is not yet understood why these fungi are more inclined to become lichens.

Traditional use

An unidentified species of ''Dictyonema'' is called ''nenendape'' by the

Huaorani The Waorani, Waodani, or Huaorani, also known as the Waos, are an Indigenous people from the Amazonian Region of Ecuador (Napo Province, Napo, Orellana Province, Ecuador, Orellana, and Pastaza Provinces) who have marked differences from other e ...

people of

Amazon jungle The Amazon rainforest, also called the Amazon jungle or Amazonia, is a moist broadleaf tropical rainforest in the Amazon biome that covers most of the Amazon basin of South America. This basin encompasses , of which are covered by the rainfo ...

of Ecuador. An

infusion Infusion is the process of extracting chemical compounds or flavors from plant material in a solvent such as water, oil or alcohol, by allowing the material to remain suspended in the solvent over time (a process often called steeping). An inf ...

made with this lichen is said to cause intense

hallucination A hallucination is a perception in the absence of an external stimulus that has the compelling sense of reality. They are distinguishable from several related phenomena, such as dreaming ( REM sleep), which does not involve wakefulness; pse ...

s, and it is used by the

shaman Shamanism is a spiritual practice that involves a practitioner (shaman) interacting with the spirit world through altered states of consciousness, such as trance. The goal of this is usually to direct spirits or spiritual energies into ...

to call upon malevolent spirits to curse people. It is also used to cause sterility.

References

* {{Taxonbar, from=Q3023415 Lichen genera Agaricales genera Basidiolichens Taxa described in 1822