Biology:Squamarina
Squamarina is a genus of lichens in the family Stereocaulaceae.[1] They form patches of radiating [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] or overlapping scales ([[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]), with a well-developed upper [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] and no lower cortex.[2] They grow on calcareous soil and rocks.[2] Squamarina lentigera can be used to make a yellow dye.[3]
Taxonomy
The genus Squamarina was circumscribed by the lichenologist Josef Poelt in 1959, with Squamarina gypsacea designated as the type species. The genus belongs to the family Lecanoraceae and was created to accommodate species previously classified under Lecanora and Psora.[4] Squamarina gypsacea, originally described by Georg Heinrich Weber as Lichen lentigerus,[5] had been transferred through various genera including Lecanora, Psora, and Parmularia before Poelt's generic reassignment. The genus name Squamarina is derived from the Latin squama (scale), referring to the characteristic [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] thallus structure of these lichens. Poelt's circumscription recognised Squamarina as distinct from related genera based on its combination of morphological and anatomical characteristics, particularly the structure of the thallus and apothecia (fruiting bodies).[4]
Description
Squamarina species form squamulose thalli—that is, mats of overlapping, scale-like [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] whose edges are often lobed again. The upper surface may carry a fine, whitish bloom ([[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]), while the sturdy [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] beneath is sharply set off from the soft interior. A green alga with spherical cells (a [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] photobiont) occupies the upper part of the thallus, and below it lies a thick, densely packed white medulla that gives the scales their firmness.[6]
Fruiting bodies are apothecia that start out concave, soon flatten and may become gently domed. Each is ringed by a rim of thallus tissue (the [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]) that is conspicuous at first but can wear away so the yellow- to red-brown [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] eventually sits flush with the scales. The disc surface is sprinkled with minute [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]] (a granular [[Glossary of lichen terms#{{biology:{1}}}|{{Biology:{1}}}]]), and the spore layer is pierced by slender, colourless threads called paraphyses. Asci conform to the Bacidia-type and contain eight colourless ascospores, each without cross-walls (aseptate). Asexual reproduction occurs in tiny flask-shaped pycnidia that release curved, hair-like conidia. Chemical tests reveal usnic acid, various β-depsidones and other still-unidentified compounds, which together help separate Squamarina from superficially similar genera.[6]
Species
As of June 2025[update], Species Fungorum (in the Catalogue of Life) accept five species of Squamarina:
- Squamarina cartilaginea (With.) P.James (1980)[7]
- Squamarina gypsacea (Sm.) Poelt (1958)
- Squamarina haysomii C.W.Dodge 1970)[8]
- Squamarina lentigera (Weber) Poelt (1958)
- Squamarina palmyrensis (H.Magn.) S.Y.Kondr. (2002)
References
- ↑ "Squamarina". Species 2000: Leiden, the Netherlands. https://www.catalogueoflife.org/data/taxon/CF439.
- ↑ 2.0 2.1 Lichens of North America. New Haven, Connecticut: Yale University Press. 2001. ISBN 0-300-08249-5.
- ↑ Brough, S. G. (1988). "Navajo lichen dyes". The Lichenologist 20 (3): 279–290. doi:10.1017/s0024282988000313. Bibcode: 1988ThLic..20..279B.
- ↑ 4.0 4.1 Poelt, J. (1958). "Die lobaten Arten der Flechtengattung Lecanora Ach. sensu ampl. in der Holarktis" (in de). Mitteilungen aus der Botanischen Staatssammlung München 19–20: 411–589. https://www.biodiversitylibrary.org/page/15188188#page/562/mode/1up.
- ↑ Weber, G.H. (1778) (in la). Spicilegium Flora Goettingensis. Sumptibus Ettingeri. p. 192. https://archive.org/details/spicilegiumflor00webegoog/page/n222/mode/2up.
- ↑ 6.0 6.1 Yahr, R.; Cannon, P.; Coppins, B.; Košuthová, A.; McCune, B.; Aptroot, A.; Simkin, J. (2025). Lecanorales: Stereocaulaceae, including Hertelidea, Lepraria, Squamarina and Stereocaulon. Revisions of British and Irish Lichens. 49. p. 14. https://britishlichensociety.org.uk/sites/default/files/Stereocaulaceae.pdf.
- ↑ Hawksworth, D.L.; James, P.W.; Coppins, B.J. (1980). "Checklist of British lichen-forming, lichenicolous and allied fungi". The Lichenologist 12 (1): 1–115 [107]. doi:10.1017/s0024282980000035. Bibcode: 1980ThLic..12....1H.
- ↑ Dodge, C.W. (1970). "Lichenological notes on the flora of the Antarctic Continent and the Subantarctic islands. IX–XI". Nova Hedwigia 19 (3–4): 439–502 [447].
Wikidata ☰ Q7581937 entry
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