• Source: Basidiolichen

Basidiolichens are lichenized members of the Basidiomycota. They form a diverse yet much smaller group of lichens than the far more common ascolichens of the Ascomycota. Basidiolichen species may be distributed in a cosmopolitan manner or more regionally, ranging from arctic and montane habitats to more temperate and tropical environments. Within and between basidiolichen genera, basidiocarp and thallus structures may vary widely. Owing to how few species there are, basidiolichens are generally considered to be poorly researched, and few studies that characterize their natural products exist.




Taxonomy


Basidiolichen mycobionts comprise 172 known species across 15 genera, 5 families, and 5 orders within the class Agaricomycetes. The majority of described basidiolichen mycobionts belong to the genus Cora, followed by the genera Dictyonema and Multiclavula. Other genera include Acantholichen, Arrhenia, Athelia, Athelopsis, Corella, Cyphellostereum, Ertzia, Lepidostroma, Lichenomphalia, Marchandiomphalina, Semiomphalina, and Sulzbacheromyces. The species Marasmiellus affixus is suggested to be yet another lichen-forming basidiomycete, but this has yet to be proven.
Basidiolichen photobionts often belong to the cyanobacterial genera Scytonema and Rhizonema or the algal genus Coccomyxa.




Biogeography


In arctic, alpine, and temperate forests, the most common basidiolichens are in the agaric genus Lichenomphalia (including former members of Omphalina or Gerronema) and the clavarioid genus Multiclavula. Several lichenized genera occur in tropical regions, the most common being the foliose Dictyonema.




Morphology


The interactions between mycobionts and photobionts in basidiolichens occur primarily at the level of the thallus. In basidiolichens of the genera Acantholichen, Cora, and Dictyonema, photobionts may be penetrated by hyphal tips called haustoria and thereby assimilated into the complete lichen thallus. In some Lepidostroma species, the hyphal tips may develop into flattened appressoria to interact with the photobiont. In species of Athelia, Athelopsis, Cyphellostereum, Lepidostroma, and especially Multiclavula, the association takes the form of globular photobiont clusters ensheathed by fungal hyphae.




Natural products


The lichen species Cora glabrata has been reported to produce a hemagglutinating lectin as well as various polysaccharides, including a unique (1→6)-linked β-D-mannan.
Tentative chemical analyses suggest that the newly described Dictyonema huaorani produces the psychedelic psilocybin. The basidiolichen was previously reported to have been used in the Ecuadorian Amazon by Huaorani shamans to call upon evil spirits and curse people.




References






External links


BioImages Several photos of Lichenomphalia umbellifera
New Zealand Fungi Images of Lichenomphalia alpina and its synonyms
The Field Museum Photos of several lichens, including Dictyonema

Kata Kunci Pencarian:

• Basidiolichen
• Dictyonema huaorani
• Lichen
• Lichenomphalia velutina
• Multiclavula ichthyiformis
• Collybiopsis affixa
• Lichenomphalia cinereispinula
• Cora trindadensis
• Lichenomphalia hudsoniana
• Multiclavula caput-serpentis