A lichen is a hybrid colony of algae or cyanobacteria living symbiotically among filaments of multiple fungi species, along with a yeast embedded in the cortex or "skin", in a mutualistic relationship.
Psora is a genus of lichen-forming fungi in the family Psoraceae. Members of the genus are commonly called fishscale lichens. Lichens in the genus Psora generally have a squamulose thallus and anthraquinones in the hymenium. Photobiont partners of Psora lichens include members of the green algal genera Asterochloris, Chloroidium, Myrmecia, and Trebouxia.
The Roccellaceae are a family of fungi in the order Arthoniales, circumscribed by French botanist François Fulgis Chevallier in 1826. This family is distinguished by a wide variety of growth forms, including crustose and fruticose thalli, and a diverse range of reproductive structures. Roccellaceae species typically have apotheciate or lirellate ascomata, often with distinct carbonised (blackened) margins. The family has been extensively studied through molecular phylogenetics, revealing significant genetic diversity and complex evolutionary histories.
The Lichinaceae are a family of ascomycete fungi. Most species are lichenized with cyanobacteria, and have a distribution largely in temperate regions.
Punctelia is a genus of foliose lichens belonging to the large family Parmeliaceae. The genus, which contains about 50 species, was segregated from genus Parmelia in 1982. Characteristics that define Punctelia include the presence of hook-like to thread-like conidia, simple rhizines, and point-like pseudocyphellae. It is this last feature that is alluded to in the vernacular names speckled shield lichens or speckleback lichens.
Lempholemma is a genus of lichen-forming fungi in the family Lichinaceae.
Zahlbrucknerella is a genus of filamentous, rock-dwelling lichens in the family Lichinaceae.
Thyrea is a genus of lichen-forming fungi in the family Lichinaceae. It contains four species that have been accepted by Species Fungorum. The genus was circumscribed by Italian lichenologist Abramo Bartolommeo Massalongo in 1856, with Thyrea plectospora assigned as the type species.
Peltula is a genus of small dark brown to olive or dark grey squamulose lichens. These lichens typically grow on rocks in arid and semi-arid environments worldwide. They consist of a fungus living in symbiosis with a photosynthetic partner, specifically a cyanobacterium of the genus Chroococcidiopsis. Peltula is the only genus in the family Peltulaceae, which belongs to the Lichinomycetes, a class of fungi that form lichens. The genus includes about 50 recognised species, which exhibit a variety of growth forms ranging from flat and crust-like to more complex, leaf-like structures. Peltula lichens play important ecological roles in harsh environments, contributing to soil stability and nutrient cycling.
The Lecideaceae are a family of lichen-forming fungi in the order Lecideales. It contains about 30 genera and roughly 250 species. A major distinguishing characteristic of the family is the lecanoroid form of the fruiting bodies: typically circular, dark, and without a thalline margin. Most species in the family are lichenised with green algae, although a few species, scattered amongst several genera, are lichenicolous—they live on other lichens. Lecideaceae lichens tend to grow on rocks, wood, and soil. Several Lecideaceae species accelerate the weathering of rock surfaces, a process known as pedogenesis, by extending their hyphae into cracks and expelling rock flakes. This contributes to significantly faster weathering rates in certain environments, impacts various materials from natural rocks to man-made Sekishu roof tiles, and involves key biomolecules identified for survival and biodeterioration, including compounds to withstand intense ultraviolet radiation.
Gregorella is a genus of lichenized fungi in the family Arctomiaceae. This is a monotypic genus, containing the single species Gregorella humida.
Lichens are symbiotic organisms made up of multiple species: a fungus, one or more photobionts and sometimes a yeast. They are regularly grouped by their external appearance – a characteristic known as their growth form. This form, which is based on the appearance of vegetative part of the lichen, varies depending on the species and the environmental conditions it faces. Those who study lichens (lichenologists) have described a dozen of these forms: areolate, byssoid, calicioid, cladoniform, crustose, filamentous, foliose, fruticose, gelatinous, leprose, placoidioid and squamulose. Traditionally, crustose (flat), foliose (leafy) and fruticose (shrubby) are considered to be the three main forms. In addition to these more formalised, traditional growth types, there are a handful of informal types named for their resemblance to the lichens of specific genera. These include alectorioid, catapyrenioid, cetrarioid, hypogymnioid, parmelioid and usneoid.
Johann Adam Philipp Hepp was a German physician and lichenologist.
Phylloblastia is a genus of foliicolous (leaf-dwelling) lichens in the family Verrucariaceae. The genus was circumscribed in 1921 by Finnish lichenologist Edvard August Vainio, with Phylloblastia dolichospora assigned as the type species.
Strangospora is a genus of lichen-forming fungi. It is the only genus in the family Strangosporaceae, which itself is of uncertain taxonomic placement in the Ascomycota. It contains 10 species.
Lempholemma polycarpum is a little-known species of saxicolous (rock-dwelling) lichen in the family Lichinaceae. It was first described from Yemen and is characterised by its blackish thallus, abundant small apothecia, and cyanobacteria from the genus Nostoc as its photobiont. The lichen is found on inclined limestone boulders in sun-exposed habitats with open forest vegetation. It also occurs in Madagascar and in Aldabra.
Pseudoheppia is a fungal genus in the family Lichinaceae. It contains a single species, Pseudoheppia schuleri, a saxicolous (rock-dwelling) squamulose lichen.
Leptogidium is a genus of lichen-forming fungi in the family Pannariaceae. It has six species.
Gloeoheppia is a genus of lichen-forming fungi in the family Gloeoheppiaceae. It comprises five species. The genus is distinguished from similar-looking lichens like Heppia by its internal structure, the nature of its photobiont, and details of its reproductive structures.
Metamelanea is a small genus of lichen-forming fungi in the family Lichinaceae. It consists of three species of rock-dwelling lichens.
