| Racoplaca | |
|---|---|
 | |
| Racoplaca melanobapha ; scale bar = 600 micrometres | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Dothideomycetes |
| Order: | Strigulales |
| Family: | Strigulaceae |
| Genus: | Racoplaca Fée (1825) |
| Type species | |
| Racoplaca subtilissima Fée (1825) | |
| Species | |
R. macrospora Contents | |
Racoplaca is a genus of lichen-forming fungi in the family Strigulaceae. [1] It comprises seven species of foliicolous (leaf-dwelling) lichens.
The genus Racoplaca was originally established by Antoine Laurent Apollinaire Fée in 1824 [2] but was later subsumed within the broader genus Strigula . A 2020 multilocus phylogenetic analysis by Shu-Hua Jiang and colleagues demonstrated that foliicolous (leaf-dwelling) species previously placed in Strigula actually represent six distinct evolutionary lineages. This led to the resurrection of Racoplaca specifically for members of the Strigula subtilissima group. The analysis showed Racoplaca forming a well-supported monophyletic clade characterised by thin, olive-brown to dark olive-green thalli with a metallic sheen, composed of dichotomously branched lobes bordered by thin black lines. [3]
The genus can be distinguished from other related genera in the Strigulaceae by its characteristic thallus morphology, the presence of black borderlines along the lobes, and its carbonised perithecial walls that are covered by a thin thallus layer up to the ostiole. [3]
Racoplaca is a genus of crustose lichens that grow on living leaves (foliicolous). The lichen forms a thin, distinctive crust beneath the leaf cuticle, characterised by repeated forking (dichotomous) branches that create a network-like pattern radiating outward. Each branch of this pattern is outlined by a thin black border. The photobiont (algal partner) in this symbiotic relationship is from the genus Cephaleuros . [3]
The sexual reproductive structures ( perithecia ) are prominent and shaped like warts or cones. These are typically covered by a thin layer of the lichen's body (thallus) except at the opening (ostiole), giving them a partially black appearance. The internal fertile tissue ( hamathecium ) is colourless and does not react with iodine-based chemical tests. The spore-producing cells (asci) are club-shaped to oblong, with a short apex ( tholus ) and narrow chamber. Each ascus produces eight colourless, two-celled ascospores arranged in two rows or irregularly. [3]
The asexual reproductive structures include small black, wart-like to conical chambers (pycnidia) that are either sunken or surface-level. These produce two types of colourless spores (conidia): larger rod-shaped to thread-like ones with two cells and short gel-like appendages at both ends (10–25 μm, never exceeding 50 μm), and smaller, single-celled, spindle to ellipsoid-shaped ones. Chemical analysis using thin-layer chromatography reveals no secondary metabolites. [3]
As of January 2025 [update] , Species Fungorum (in the Catalogue of Life) accept seven species of Racoplaca: [4]
Byssoloma is a genus of leaf-dwelling lichens in the family Pilocarpaceae.
Mazosia is a genus of lichen-forming fungi in the family Roccellaceae.
Gallaicolichen is a fungal genus that contains the single species Gallaicolichen pacificus, a foliicolous (leaf-dwelling) lichen. Originally discovered in Hawaii in 2007, G. pacificus has since been found in various locations across the Pacific, including Australia, New Caledonia, Vanuatu, the Philippines, and Japan. The lichen forms small, pale greenish-yellow to yellowish-grey patches on leaves, typically in mid-altitude forests and along forest edges. G. pacificus is notable for its unique reproductive structures called peltidiangia, which produce disc-shaped propagules (peltidia) for asexual reproduction. Initially, its taxonomic classification was uncertain, but recent discoveries of specimens with sexual reproductive structures have enabled scientists to confidently place it within the family Porinaceae.
Briancoppinsia is a fungal genus in the family Arthoniaceae. It is monotypic, containing the single species Briancoppinsia cytospora, a lichenicolous fungus that parasitises parmelioid lichens, as well as Cladonia, Lepra, and Lecanora conizaeoides, among others. The species was first described scientifically by Léon Vouaux in 1914 as Phyllosticta cytospora.
Emmanuël Sérusiaux is a Belgian lichenologist. His career, spanning more than four decades, has combined both lichenology research and political aspects of nature conservation. He spent several periods working as a researcher at the National Fund for Scientific Research and the University of Liège, the latter in which he accepted a faculty position as professor and head of the Plant Taxonomy and Conservation Biology unit. Sérusiaux also served for three non-consecutive appointments as Deputy Chief of Staff in the Government of Wallonia. He retired from both his academic and political positions in 2019.
Strigulaceae is a family of lichen-forming fungi, one of two families in the order Strigulales. Recent (2020) molecular analysis of the type genus, Strigula, has led to a reallocation of the foliicolous species into six genera that correspond to well-delimited clades with diagnostic phenotype features.
Strigula is a genus of lichen-forming fungi in the family Strigulaceae. The genus was circumscribed in 1823 by English mycologist Elias Magnus Fries.
Serusiauxiella is a genus of leaf-dwelling lichens in the family Strigulaceae. It has three species, all of which are found in wet tropical forests in China. The genus was circumscribed in 2020 by Shu-Hua Jiang, Robert Lücking, and Jiang-Chu Wei, with Serusiauxiella filifera assigned as the type species. The genus name honours Belgian lichenologist Emmanuël Sérusiaux, "in recognition of his important contributions to lichenology, foliicolous lichens and the genus Strigula".
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.
Strigulales is an order of lichen-forming fungi in the class Dothideomycetes. It contains two families: Strigulaceae and Tenuitholiascaceae, with a combined total of 115 species. The order was proposed by Robert Lücking, Matthew Nelsen, and Kevin Hyde in 2013. Most species in the order are foliicolous, that is, they grow on plant leaves.
Swinscowia is a genus of lichen-forming fungi in the family Strigulaceae. It has 34 species. Swinscowia was proposed in 2020 by lichenologists Shu-Hua Jiang, Robert Lücking, and Emmanuël Sérusiaux to contain non-foliicolous species that were isolated from bark and rocks. Swinscowia jamesii, a species that was originally described in genus Geisleria, and later transferred to Strigula, is the type species of the genus. The genus name honours British lichenologist Dougal Swinscow, who originally described the type species in 1967.
Tenuitholiascus is a fungal genus in the monotypic family Tenuitholiascaceae, itself in the order Strigulales. The genus contains a single species, Tenuitholiascus porinoides, a foliicolous (leaf-dwelling) lichen found in China.
Aspidothelium is a genus of lichen-forming fungi in the family Thelenellaceae. All species in the genus have a tropical distribution and are crustose with a chlorococcoid photobiont partner. Most Aspidothelium species are foliicolous (leaf-dwelling), although some corticolous (bark-dwelling) species are known, as well as a single saxicolous (rock-dwelling) member.
Macroconstrictolumina is a genus of lichen-forming fungi in the family Trypetheliaceae. It has four species.
Fellhanera ivoriensis is a species of foliicolous (leaf-dwelling) lichen. First described in 2001, this species is distinguished from its relatives in the Fellhanera by its soredia-covered thallus and the characteristics of its apothecia. It is native to the Ivory Coast in West Africa.
The Pyrenotrichaceae are a small family of fungi in the order Chaetothyriales. It contains two genera, and a total of six species. The genus Pyrenothrix has two species of bark- or leaf-dwelling lichens, while Neophaeococcomyces has four species of saprobic fungi.
Microtheliopsis is a genus of lichen-forming fungi in the family Microtheliopsidaceae. It comprises four species of foliicolous (leaf-dwelling) crustose lichens.
Oletheriostrigula is a fungal genus in the family Strigulaceae. It comprises the single species Oletheriostrigula papulosa. This microscopic fungus was first described in 1848 and has undergone several taxonomic reclassifications before being placed in its own genus in 1996. Unlike the vast majority of the Strigulaceae, O. papulosa does not form a symbiotic relationship with algae. It produces small, spherical fruiting bodies (ascomata) that grow on dead plant material, particularly on plants with durable or persistent leaves. The fungus has a widespread distribution, favouring warm climates, and plays a role in decomposition processes. O. papulosa is characterised by its unique combination of morphological features, including apically free paraphyses with bulbous tips, and its ability to produce both sexual and asexual spores.
Batistomyces is a small genus of fungi in the family Gomphillaceae. It has two species of leaf-dwelling (foliicolous) lichens. These microlichens form very thin layers on the surface of leaves, appearing to the naked eye as small, fuzzy dark patches due to their numerous short black bristles.
Sipmanidea is a small genus of fungi in the family Gomphillaceae. It comprises two species of leaf-dwelling lichens.