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 Ramalinaceae are a family of lichen-forming fungi in the order Lecanorales. First proposed by Carl Adolph Agardh in 1821, the family now comprises 63 genera and about 750 species. Ramalinaceae lichens exhibit diverse growth forms, including crustose, fruticose, squamulose, leprose, and byssoid thalli, and form symbiotic relationships primarily with green algae of the genus Trebouxia. The family is characterised by pale-coloured thalli, apothecia that are typically pale but may darken with age, and ascospores that vary in shape and septation.
Chrysothrix candelaris, commonly known as the mustard powder lichen or gold dust lichen, is a species of leprose (powdery) lichen in the family Chrysothricaceae. It typically grows on tree bark, although it has also been recorded growing on rock. It does not show ascocarps or other reproductive structures, belonging to the group commonly known as the 'Fungi or lichens imperfecti' in the UK.
Schadonia is a genus of lichen-forming fungi. Established by German lichenologist Gustav Wilhelm Körber in 1859, this genus of crustose lichens is characterised by its black, sessile apothecia, muriform ascospores, and growth on mosses, plant debris, and rocks in montane habitats. While traditionally placed in the family Ramalinaceae, recent studies have suggested its classification may be uncertain within the order Lecanorales, with some researchers proposing its placement in the Pilocarpaceae or the resurrection of the family Schadoniaceae. The genus currently comprises four recognised species.
Vermilacinia, a genus of lichenized fungi in the family Ramalinaceae, is a yellow-green fruticose type of lichen with about 30 species that grow on rocks, trees, and soil within the fog zone along the Pacific Coast of North America and South America. The genus name refers to the thallus being divided into narrow worm-like (vermis) branches (lacinia);the latter part of the name (lacinia) generally applied in descriptions and taxonomic keys such as exemplified in a key to Sonoran Desert species of Ramalina.
Xanthoparmelia is a genus of foliose lichens in the family Parmeliaceae. This genus of lichen is commonly found in the United States, South America, southern Africa, Europe, Australia, and New Zealand.
Lepraria santosii is a species of crustose lichen in the family Stereocaulaceae. It occurs in Tenerife, in the Canary Islands.
Chrysothrix insulizans is a species of leprose lichen in the family Chrysotrichaceae. It is a distinctive species of lichen characterized by its bright yellow-green to yellow-orange coloring and unique growth patterns. Most collections have been found growing on rocks, although a few have been recorded growing on bark.
Verseghya thysanophora, commonly known as the mapledust lichen, is a species of mostly corticolous (bark-dwelling), leprose lichen in the family Pertusariaceae. This common species is widely distributed in the Northern Hemisphere. The thallus of the lichen is a thin patchy layer of granular soredia, pale green to yellowish green in colour. The main characteristics of the lichen include the presence of lichen products known as thysanophora unknowns, and the conspicuous white, fibrous prothallus that encircles the thallus.
Chrysothrix chlorina, the sulphur dust lichen, is a species of leprose (powdery) crustose lichen in the family Chrysotrichaceae. Originally described scientifically by the Swedish lichenologist Erik Acharius over 200 years ago, it has been shuffled to many different genera in its taxonomic history before finally being transferred to Chrysothrix in 1981. The lichen has a circumboreal distribution, meaning it occurs in northern boreal regions across the planet. It is typically saxicolous (rock-dwelling), particularly on the underside of rock overhangs, but has in rare instances been recorded growing on bark and various other surfaces.
Usnochroma is a genus of lichen-forming fungi in the family Teloschistaceae. It has two species of crustose lichens. The genus was circumscribed in 2013 by lichenologists Ulrik Søchting, Ulf Arup, and Patrik Frödén, with Usnochroma carphineum assigned as the type species. The genus name refers to the yellowish-green colour of the thallus, which is caused by the substance usnic acid. Usnochroma species occur in Macaronesia, South Africa, the Mediterranean Basin, and Algeria.
Chrysothrix tchupalensis is a little-known species of saxicolous (rock-dwelling), powdery lichen in the family Chrysotrichaceae. It occurs in north Queensland, Australia. The lichen forms a powdery, bright yellow thallus that grows on sheltered, humid rocks in a tropical rainforest environment.
Rhizoplaca ouimetensis is a saxicolous (rock-dwelling), crustose lichen species in the family Lecanoraceae. Uniquely identified by its sorediate form—a feature not observed in other Rhizoplaca species—it was discovered in Ontario, Canada, specifically within the Ouimet Canyon Provincial Park.
Myochroidea is a genus of lichen-forming fungi of uncertain familial placement in the order Lecanorales. It has four species of grey or brown-grey crustose lichens.
Lepraria bergensis is an uncommon crustose lichen in the family Stereocaulaceae. It occurs in Northern and Central Europe, where it grows on siliceous (silicon-rich) rock walls, particularly under small overhangs, and on mosses on vertical to slightly sloping rock surfaces. The lichen thallus forms as a pale bluish-grey crust-like growth on rocks and mosses. The lichen begins as small, rounded patches a few millimetres wide, which may eventually coalesce into larger areas exceeding 1 centimetre in diameter. The thallus has a powdery texture, consisting of minute granules known as soredia and consoredia, which facilitate the lichen's asexual reproduction. The chemical composition of Lepraria bergensis is distinguished by the presence of several secondary metabolites: atranorin, rangiformic acid or jackinic acid, trace amounts of their respective derivatives, and a variety of anthraquinones. These chemical components cause the lichen to fluoresce a dull yellow under long-wave ultraviolet light.
Xanthoparmelia cranfieldii is a species of foliose lichen in the family Parmeliaceae, first described by John Elix in 2003. It is known only from its type locality in Western Australia.
Megaloblastenia is a genus of crustose lichen-forming fungi in the family Megalosporaceae, comprising three species. Proposed by Dutch lichenologist Harrie Sipman in 1983, the genus is characterised by its thick, ecorticate thallus ranging from pale whitish-grey to yellowish, and its disc-like fruiting bodies (apothecia) that can be biatorine or lecideine. Megaloblastenia lichens form a symbiotic relationship with Dictyochloropsis algae, produce hyaline, bicellular ascospores with polaribilocular structure, and contain chemical compounds such as zeorin, pannarin, or usnic acid. Found in Australasia and South America, these lichens typically grow as epiphytes on trees in moist forests within temperate to tropical oceanic climates.
Ramalina europaea is a species of fruticose lichen in the family Ramalinaceae. This species is widely distributed across Europe and is distinguished by its small, punctiform (point-like) soralia that often develop terminally on spine-like branchlets.
Parallopsora is a small genus of lichen-forming fungi in the family Ramalinaceae. Established in 2018, the genus contains three species that were previously classified under a related genus, Phyllopsora. These lichens form small, scale-like growths that overlap like roof tiles and typically appear pale green to bluish-green in colour. They reproduce through both small brown fruiting bodies and sometimes through powdery structures on their surface. The species are known to grow in tropical rainforests, particularly in Brazil, Peru and Cuba.
Pseudolepraria is a fungal genus in the family Ramalinaceae. It comprises the single species Pseudolepraria stephaniana, a corticolous (bark-dwelling) leprose lichen found only in lowland tropical forests of Bolivia. First described as Lepraria stephaniana in 2010, the species was reclassified into its own genus in 2023 after molecular studies revealed its distinct phylogenetic position. The lichen is characterised by its thick, powdery, green-grey to creamy-white thallus lacking defined edges, and is notable for containing the rare compound 4-O-methylleprolomin. Unlike related Bolivian Lepraria species that occur at higher elevations, P. stephaniana is found only at altitudes between 300 and 470 metres above sea level in transitional zones between Chaco and Amazon rainforest types.
