Overview

Brief Summary

Description

 Thallus: placodioid, 1.5-3.5 cm or more wide, 0.5-2 mm or more thick in center, primarily forming neat rosettes, but often either confluent or +dispersed and irregular, tightly to loosely attached; areolate to squamulose; prothallus: absent or vestigial, with the outermost edges and especially the extreme lobe tips often darkened blue-green to black; areoles: contiguous or +scattered, irregularly +round, 0.5-1 mm wide; edges: sometimes raised and thickened; lobes: radiating to randomly oriented, contiguous to discrete, 1.5-4.5(-6) mm long, 0.5-0.6(-1.5) mm wide, sometimes short and squamule-like, plane, concave, convex, or undulate with the edges folded along sinuses, but not sinuous-plicate; edges: plane or raised and thickened especially towards tips; simple to incised-crenate, the ultimate segments 0.3-1 mm wide; upper surface: grayish yellow green to pale greenish yellow, grayish yellow, more yellow towards the lobe tips (in herbarium becoming medium yellow to pale brown or orange; coastal forms: often very pale yellowish green), continuous to rimose, +shiny or waxy; usually pruinose on margins (especially folded sinuses), or +spotily pruinose on warty areas near lobe tips (v. versicolor), or entire surface becoming +densely pruinose (e.g., albopulverulenta), esorediate; upper cortex: cone cortex type, without dead algal cells, 50-75 µm or more thick, inspersed with yellowish granules (soluble in K, insoluble in N); hyphae: randomly oriented to anticlinal, 3-5 µm in diam.; lumina: c. 2 µm wide; epinecral layer: 5-10(-15) µm thick; medulla: solid but rather loose and cottony; algal layer: unevenly thickened and divided; lower surface: white, or pale to deep yellow or brown, or at least partly blue-green to black; lower cortex: mostly confined to areas near the tips or margins of the lobes, indistinct and poorly developed; Apothecia: few to crowded towards thallus center, borne marginally or submarginally, one to several per areole, subimmersed then +broadly sessile, 0.8-1.8(-2.3) mm in diam.; disc: often varying on the same thallus from light yellow to pale to dark yellow, orange- or red-brown or blackening or sometimes greenish gray near the margin, plane or sometimes convex, dull or shiny, epruinose; margin: concolorous with thallus or pale yellow to pale orangish yellow, +raised then level with disc, 0.1-0.3 mm wide, dull or shiny, occasionally with thin white outer edge or thin black outer edge, sometimes +completely pruinose, entire to flexuous or crenate, finally excluded, often with a very distinct, +yellow to brown parathecial ring; amphithecium: present, with an interrupted algal layer c. 50 µm thick located mostly next to the parathecium, sometimes with granules or a few coarse hyaline crystals (insoluble in K) in the medulla, corticate; cortex: similar in structure to that of thallus; parathecium: hyaline, weakly differentiated from hypothecium, with conglutinated, thick-walled hyphae 3-5 µm wide and with narrow (1-2 µm) lumina; epihymenium: inspersed with fine granules (soluble in K); hymenium: hyaline, 50-70 µm tall; paraphyses: tips thin and hyaline or pale brown; subhymenium: pale yellowish brown, 18-25(-50) µm; hypothecium: hyaline to pale yellow, 25-50 µm thick (to 150-300 µm thick in center or in areas where hyphal bundles extend into the algal layers), hyphae randomly oriented; asci: clavate, 8-spored; ascospores: hyaline, simple, +ellipsoid, 8-13(15) x (3.5-)4.5-7 µm; Pycnidia: infrequent, scattered, and inconspicuous, immersed; conidiophores: type III of Vobis (1980); Spot tests: thallus (in the Sonoran region) usually K-, C-, KC-, P-; cortex usually KC+ yellow; medulla usually KC-; Secondary metabolites: cortex with usnic acid, or occasionally (e.g., v. brunneola) isousnic acid; medulla almost always with zeorin, usually also leucotylin, other triterpenes, and fatty acids, and occasionally various depsides, depsidones or unknowns.; Substrate and ecology: on basalt, pumice, rhyolite, granite, sandstone, and limestone; occasional on bark, in a wide range of communities; World distribution: eurytemperate, subcosmopolitan in Europe, Asia, North America, South America, Africa, Macaronesia, Oceania, and Australasia; Sonoran distribution: Arizona, southern California, Baja California, Baja California Sur, and Sonora, at 20-2800 m.; Notes: As delimited here, Lecanora muralis is an extremely variable taxon, probably representing a complex of species. Some of the more distinctive variants in our region are var. brunneola (Mereschk.) B.D. Ryan & T.H. Nash, with brown thallus containing isousnic instead of or in addition to usnic acid (Arizona), and ssp. dubyi (Müll. Arg.) Poelt s. lato, with coarse, thick, often loosely attached lobes (widespread). There are a number of chemical variations, including a few populations lacking leucotylin; in Eurasia some of these chemical variations appear to correlate with morphological characters and have been named as separate specific or infraspecific taxa; much further study of these is needed before any of these names can be applied to North (or South) American material. Material from Santa Catalina Island, collected in 1895 by Hasse, was referred to by Hasse (1903b) as var. catalinae Stizenb. (nomen nudum); examination of material in NY annotated as this taxon by Hasse shows that it fits well within typical var. muralis as delimited in the present treatment. 
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Lichen Unlimited: Arizona State University, Tempe.

Source: Lichen Flora of the Greater Sonoran Desert Region

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Comprehensive Description

General Description

Crustose lichen, forming striking, beautiful, greenish, lobate rosettes (sometimes confluent with nearby thalli) on most kinds of rock. At first closely-appressed, but in age the center buckles out and often comes off the rock completely. Abundant brownish to yellowish to orangish to greenish apothecia (often variably colored on the same thallus) packed tightly in the center. Lobe tips are somewhat thickened around the edge making them look a bit concave. Typically waxy in appearance, although it can be pruinose esp. near the tips. Though technically crustose, they often form a rudimentary lower cortex near the lobe tips, making them “honorary foliose” lichens.

 

One of the few (of many many) Lecanora that can be more-or-less reliably identified in the field. It is, however, a rather variable species, with several subspecies and varieties defined throughout the world. It can be non-pruinose or heavily pruinose, gray or greenish or yellowish, abundantly fertile or sparsely so, with strongly radiating or randomly overlapping lobes, and has light-colored but extremely variably-colored apothecia.

Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

© Jason Hollinger

Source: Mushroom Observer

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Distribution

National Distribution

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

United States

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Worldwide, cosmopolitan, often one of few lichens thriving in or near cities.

Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

© Jason Hollinger

Source: Mushroom Observer

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Physical Description

Diagnostic Description

LOBES: distinctly lobate, lobes plane to concave, grayish to pale yellowish-green to pale greenish-yellow, shiny-waxy texture, epruinose or not
 ANATOMY: medulla loose and cottony, algal layer discontinuous
 APOTHECIA: packed in center, discs pale yellowish to orangish to brownish, epruinoes; rim distinct, continuous, like thallus
 CHEMISTRY: cortex usually KC+ gold (usnic acid)

Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

© Jason Hollinger

Source: Mushroom Observer

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Look Alikes

Other relatively-common, strongly-lobate, rosette-forming Lecanora:

 

L. garovaglii: lobes typically wider and thicker with a folded or inflated appearance
 L. sierrae: lobes also wider and thicker, typically yellower
 L. mellea and L. pseudomellea: brown or brownish
 L. novomexicana: pruinose apothecia
 L. phaedrophthalma: less distinctly lobate, darker apothecia?
 L. bipruinosa: pruinose apothecia
 L. valesiaca: thallus heavily pruinose, weakly separated lobes

 

Among several others…

Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

© Jason Hollinger

Source: Mushroom Observer

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Ecology

Habitat

Most kinds of rock, in exposed situations, esp. enriched by birds, drip-zones, etc.

Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

© Jason Hollinger

Source: Mushroom Observer

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Conservation

Conservation Status

National NatureServe Conservation Status

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: NNR - Unranked

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

NatureServe Conservation Status

Rounded Global Status Rank: G5 - Secure

Reasons: This lichen species grows on sandstone, granite, and calcareous rock throughout the United States, including Alaska, and southern Canada.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Wikipedia

Lecanora muralis

Lecanora muralis is a waxy looking, pale yellowish green crustose lichen that usually grows in rosettes radiating from a center (placoidiod) filled with disc-like yellowish-tan fruiting bodies (apothecia).[1] It grows all over the world.[2] It is extremely variable in its characteristics as a single taxon, and may represent a complex of species.[2] The fruiting body parts have rims of tissue similar to that of the main nonfruiting body (thallus), which is called being lecanorine.[1] It is paler and greener than L. mellea, and more yellow than L. sierrae.[1] In California, it may be the most common member of the Lecanora genus found growing on rocks (saxicolous).[1]

Substrates and distribution[edit]

It grows on rock including basalt, pumice, rhyolite, granite, sandstone, and limestone.[2] Sometimes it can be found growing on bark.[2] It may be tightly or loosely attached to the substrate.[2]

It grows all over the world including in Europe, Asia, North America, South America, Africa, Macaronesia, Oceania, and Australasia.[2] In California, it may be the most common member of the Lecanora genus found growing on rocks (saxicolous).[1] In the Sonoran Desert it is found from southern California to both north and south Baja California, and through Arizona to Sonora, Mexico, at elevation ranges from 20 to 2,800 metres (66 to 9,186 ft).[2]

Description[edit]

L. muralis showing lobes on thallus margin

The usually 1.5–3.5 cm (or more) wide nonvegetative body (thallus) is made up of parts separated by cracks (areolate) that may lift at their edges (squamulose), usually growing in a neat rosette radiating from the center (placodioid in lobes.[2] The upper surface is pale grayish to yellow-green, being more yellow towards the lobe tips.[2] It may be continuous to rimose, with a surface that is shiny or waxy.[2]

Contiguous or widely separated lobes radiate outward, but may be randomly oriented. The lobes are roughly 1.5–4.5 mm long, and 0.5–0.6 mm wide.[2] Lobes are sometimes short and like squamules.[2] They may be concave, convex, or undulate, with their edges folded along sinuses, but never sinuous to plicate.[2] Like the areolas, the edges of the lobes may be flat like planes, or raised, theickening towards tips.[2] The ends of the lobes may be simple or incised to crenate.[2] The extreme tips of the lobes are in segments that are 0.3–1 mm wide.[2] The outer edges of the lobes are darkener, sometimes being blue-green to black.[2] The center is 0.5–2 mm (or more) thick.[2]

The prothallus is either absent or vestigial, with areoles sometimes being contiguous and sometimes scattered.[2] The 0.5–1 mm wide areaolas may be irregular to round, with edges that are sometimes raised (squamulous), and thickened where they raise up.[2] Coastal forms are more pale yellowish green than gray.[2]

It usually does not have a coating of fine dustlike particles (pruinose),[1] but sometime may, especially at the margins, especially where the sinuses are folded.[2] There are no particles are little granules of algae wrapped in fungi, for propagation (soredia) to the point of being densely covered in chalky white material (albopulverulenta), but soredia may be entirely lacking (esorediate).[2]

The apothecia may be few to very crowded at the thallus center. There may be none to many that are borne at or near the margin of the areoles.[2] The apothecia disc is rimmed with tissue that is yellowish, similar to that of the thallus.[2] The center of the apothecia is orange to red-brown, sometimes greenish gray to black near the margins.[2]

Cross section[edit]

The upper cortex is of the cone cortex type, with no dead algal cells, and is 50–75 µm (or more) thick with yellowish granules interspersed.[2] These granules are soluble in potassium (K).[2] The fungal filaments (hyphae) of the upper cortex are either randomly oriented to becoming anticlinal, and are 3–5 µm in diameter.[2] Lumina are 2 µm wide.[2] The medulla is loosely solid and cottony.[2] The algal layer is thickened and divided into a lower surface that is white or pale to deep-yellow or brown.[2] There may be a slight but indistinct and poorly developed lower cortex at the tips of the lobes.[2]

Spot tests and secondary metabolites[edit]

Lichen spot tests on the thallus in Sonoran Desert populations are usually K-, C-, KC-, and P-.[2] Spot tests of the cortex usually are KC+ yellow to gold. Spot tests of the medulla are usually KC-.[2] Secondary metabolites include usnic acid in the cortex, sometimes with isousnic acid.[2] The medulla has zeorin, and usually leucotylin and other triterpenes and fatty acids.[2]

See also[edit]

References[edit]

  1. ^ a b c d e f Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, ISBN 978-0-300-19500-2, page 279
  2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak Lichen Flora of the Greater Sonoran Desert Region. Vol 2, Nash, T.H., Ryan, B.D., Gries, C., Bugartz, F., (eds.) 2001., [1]
Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Default rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!