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Myriolecis

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Myriolecis
Myriolecis dispersa
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Lecanoromycetes
Order: Lecanorales
Family: Lecanoraceae
Genus: Myriolecis
Clem. (1909)
Type species
Myriolecis sambuci
(Pers.) Clem. (1909)
Synonyms[1]
  • Arctopeltis Poelt (1983)

Myriolecis is a genus of lichen-forming fungi in the family Lecanoraceae.[2] These lichens typically form thin, crusty patches on rocks, bark, or soil, and reproduce through small disc-shaped structures that contain spores. The genus was reinstated in recent years when DNA studies showed that these species form a distinct group separate from the closely related genus Lecanora.

Taxonomy

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The genus was originally circumscribed in 1909 by Frederic Clements with Myriolecis sambuci as the type species.[3] The genus was later reinstated to accommodate the Lecanora disperse group and Arctopeltis. Molecular phylogenetics data showed that this group of species formed a clade that is genetically distinct from Lecanora,[4][1] and Myriolecis was the oldest name available to hold these species.[1]

Description

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Myriolecis species grow as thin, crust-like patches that are usually sunk into the surface they inhabit, whether that is rock, bark or soil. Where the thallus (the lichen body) protrudes, it can crack into tiny island-like plates called areoles or break up into scattered granules, but it never forms the powdery eruptions known as soredia, the finger-like projections called isidia or the cyanobacterial swellings termed cephalodia. The photosynthetic partner is most often a single-celled green alga from the genus Trebouxia, although closely related algae may substitute in some species.[5]

The sexual fruit-bodies (apothecia) sit directly on the thallus and are occasionally lifted on a very short stalk. Each disc starts with a conspicuous rim of thallus tissue that is white or matches the thallus colour; this margin may become wavy or disappear as the apothecium ages. A distinct supporting wall (true exciple) is largely absent, but the disc's surface layer (epithecium) carries brown pigments that can clump into tiny grains. Beneath this, the spore-bearing layer (hymenium) is almost colourless and stains blue when treated with iodine, confirming the Lecanora-type ascus—a slender club that typically contains eight colourless, one-celled ascospores with smooth, sometimes thickened walls. Minute, flask-shaped pycnidia embedded in the thallus produce asexual spores: tiny rods that may be straight, curved or sickle-shaped. Across the genus, chemical composition is variable; individual species manufacture different suites of lichen products—depsides, depsidones, terpenoids or xanthones—that can help in species identification.[5]

Species

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References

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  1. ^ a b c Zhao, Xin; Leavitt, Steven D.; Zhao, Zun Tian; Zhang, Lu Lu; Arup, Ulf; Grube, Martin; Pérez-Ortega, Sergio; Printzen, Christian; Śliwa, Lucyna; Kraichak, Ekaphan; Divakar, Pradeep K.; Crespo, Ana; Lumbsch, H. Thorsten (2016). "Towards a revised generic classification of lecanoroid lichens (Lecanoraceae, Ascomycota) based on molecular, morphological and chemical evidence". Fungal Diversity. 78 (1): 293–304. doi:10.1007/s13225-015-0354-5.
  2. ^ "Myriolecis". Catalogue of Life. Species 2000: Leiden, the Netherlands. Retrieved 18 June 2025.
  3. ^ Clements, Frederic E. (1909). The genera of Fungi. Minneapolis: The H. W. Wilson Co. pp. 79, 175.
  4. ^ Śliwa, Lucyna; Miadlikowska, Jolanta; Redelings, Benjamin D.; Molnar, Katalin; Lutzoni, François (2012). "Are widespread morphospecies from the Lecanora dispersa group (lichen-forming Ascomycota) monophyletic?". The Bryologist. 115 (1): 265–277. doi:10.1639/0007-2745-115.2.265. JSTOR 23321028.
  5. ^ a b Cannon, P.; Malíček, J.; Ivanovich, C.; Printzen, C.; Aptroot, A.; Coppins, B.; Sanderson, N.; Simkin, J.; Yahr, R. (2022). Lecanorales: Lecanoraceae, including the genera Ameliella, Bryonora, Carbonea, Claurouxia, Clauzadeana, Glaucomaria, Japewia, Japewiella, Lecanora, Lecidella, Miriquidica, Myriolecis, Palicella, Protoparmeliopsis, Pyrrhospora and Traponora (PDF). Revisions of British and Irish Lichens. Vol. 25. p. 61.Open access icon
  6. ^ a b Mamut, Reyim; Li, Pan; Abbas, Abdulla; Fu, Chengxin (2019). "Morphology, chemistry and molecular phylogeny revealed a new species and a new combination of Myriolecis (Lecanoraceae, Ascomycota) from China". The Bryologist. 122 (3): 375–383. doi:10.1639/0007-2745-122.3.375.
  7. ^ Bertrand, Michel; Monnat, Jean-Yves; Lohézic-Le Dévéhat, Françoise (2018). "Myriolecis massei, a new species of Lecanoraceae from the coasts of the Armorican Massif in Western Europe". The Bryologist. 121 (3): 253–263. doi:10.1639/0007-2745-121.3.253.
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