| Schizotrema | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Graphidales |
| Family: | Graphidaceae |
| Genus: | Schizotrema Mangold & Lumbsch (2009) |
| Type species | |
| Schizotrema zebrinum Mangold (2009) | |
| Species | |
S. flavolucens Contents | |
Schizotrema is a genus of lichen-forming fungi in the family Graphidaceae. The genus was circumscribed in 2009 by Armin Mangold and H. Thorsten Lumbsch. [1]
The genus Schizotrema consists of lichens with a thallus that can range from being immersed in the substrate to appearing more superficial. The thallus is usually pale in colour and often inconspicuous. Its photosynthetic partner, or photobiont , is a green alga from the genus Trentepohlia . The prothallus , a structure that sometimes surrounds the edges of the lichen, is faint and brown, blending subtly with the substrate. Some species produce soralia, which are small, discrete, and punctiform (dot-like) structures that release powdery reproductive propagules for asexual reproduction. [2]
The ascomata, or sexual reproductive structures are generally rounded and embedded within the thallus. These structures are surrounded by a thick, layered thalline rim , which may flake away as the lichen ages. The true exciple , the tissue surrounding the spore-producing region, is dark brown to black and multilayered. It may or may not react with iodine at its base (amyloid or non-amyloid) and is lined with small hair-like structures known as periphysoids . [2]
Internally, the hymenium (spore-producing region) is tightly packed and does not react to iodine staining (non-amyloid). The hamathecium , the network of sterile filaments within the hymenium, is composed of unbranched paraphyses with tips that are not thickened. The asci, which are sac-like structures where spores develop, are clavate (club-shaped) and contain between one and eight spores. These asci also do not react to iodine. The spores produced by Schizotrema are transversely septate (divided by cross-walls) or muriform (divided into multiple compartments by both transverse and longitudinal walls). They are hyaline (colourless) to yellowish, sometimes becoming brown at full maturity, and may have a thin gelatinous coating. Asexual reproductive structures called conidiomata have not been observed to occur in this genus. [2]
The species once known as Schizotrema cryptotrema(Nyl.) Rivas Plata & Mangold (2010) is now Cryptoschizotrema cryptotrema . [6]
The Graphidaceae are a family of lichen-forming fungi in the order Graphidales. The family contains nearly a hundred genera and more than 2000 species. Although the family has a cosmopolitan distribution, most Graphidaceae species occur in tropical regions, and typically grow on bark.
Ochrolechia is the sole genus in the fungal family Ochrolechiaceae. It comprises about 40 species of crustose lichens. These lichens typically form uneven, often thick, crust-like growths on various surfaces and are characterised by their white to pale grey thalli, which may have a greenish tint. The genus has a long evolutionary history, with fossils dating back to the Paleogene period, about 34 million years ago. Ochrolechia species have disc-like apothecia, which are usually yellowish or brownish-pink and often covered with a fine white powdery coating. The genus is widely distributed and includes both common and rare species, with some found in extreme environments such as arctic and alpine regions. Ochrolechia lichens produce diverse secondary metabolites, including orcinol depsides, depsidones, and xanthones.
Phaeographis is a genus of lichen-forming fungi in the family Graphidaceae. It has an estimated 180 species.
Myriotrema is a genus of lichen-forming fungi in the family Graphidaceae.
Diploschistes is a genus of lichen-forming fungi in the family Graphidaceae. Commonly known as crater lichens, members of the genus are crustose lichens with a thick, cracked (areolate) body (thallus) with worldwide distribution. The fruiting part (apothecia) are immersed in the thick thallus so as to have the appearance of being small "craters". The widespread genus contains about 43 species.
Chapsa is a genus of lichens in the family Graphidaceae. The genus was circumscribed by Italian lichenologist Abramo Bartolommeo Massalongo in 1860.
Thelotrema is a genus of lichen-forming fungi in the family Graphidaceae, the family to which all taxa in the former Thelotremataceae now belong.
Arthothelium is a genus of lichen-forming fungi in the family Arthoniaceae.
Mazosia is a genus of lichen-forming fungi in the family Roccellaceae.
Astrochapsa is a genus of lichen-forming fungi in the subfamily Graphidoideae of the family Graphidaceae. It has 28 species. The genus was circumscribed by Sittiporn Parnmen, Robert Lücking, and H. Thorsten Lumbsch in 2012, with Astrochapsa astroidea assigned as the type species. It was segregated from the genus Chapsa, from which it differs in having a more frequently densely corticate thallus, an apothecial margin that is mostly recurved, and the almost exclusively subdistoseptate, non-amyloid ascospores.
Graphidales is an order of lichen-forming fungi in the class Lecanoromycetes. It contains 6 families, about 81 genera and about 2,228 species. Family Graphidaceae are the largest crustose family within Graphidales order comprising more than 2000 species, which are widely distributed in tropical and subtropical regions of the world.
Clandestinotrema is a genus of lichen-forming fungi in the family Graphidaceae. It has 18 species. They typically inhabit montane and cloud forest at higher elevations in the tropics.
Gintarasia is a genus of lichen-forming fungi in the family Graphidaceae. It has seven species, all of which are found in Australia. Gintarasia species are corticolous (bark-dwelling), crustose lichens with a thelotremoid form.
Ocellularia vizcayensis is a rare species of corticolous (bark-dwelling) lichen in the family Graphidaceae. It is known from a single collection made in Luzon, Philippines. The lichen thallus is a white, irregularly structured, areolate surface with a layer that includes a photosynthetic partner, both containing large calcium oxalate crystals. Its fruiting bodies are either embedded or protruding, round, with very narrow openings, and contain large, oblong, colorless spores that turn violet-blue when stained with iodine.
Pycnotrema is a small genus of lichen-forming fungi in the family Graphidaceae. Its two species are characterised by their small, rounded apothecial pores.
Glaucotrema is a genus of lichen-forming fungi in the family Graphidaceae. It has five species.
Crutarndina is a monotypic fungal genus in the family Graphidaceae. It contains the single species Crutarndina petractoides, a corticolous (bark-dwelling), crustose lichen.
Melanotopelia is a genus of lichen-forming fungi in the family Graphidaceae. It has four species of corticolous (bark-dwelling), crustose lichens. This genus includes species characterised by dark pigmentation in their exciple, non-amyloid ascospores, and specific secondary metabolites.
Corticorygma is a monotypic fungal genus in the subfamily Graphidoideae of the family Graphidaceae. It contains a single species, the corticolous (bark-dwelling) crustose lichen Corticorygma stellatum. This script lichen is found in the shaded understory of rainforests in the Brazilian states of Rondônia and Paraná.
