Xantho- and Flavo- Parmelias

Trying to avoid guessing about the saxicolous yellow-green parmelias, for the most part, especially from photos, with no chemistry available. Looks like it's going to be important to check the underside on these.

See Xanthos at http://www.sharnoffphotos.com/lichensH/lichens15_index.html
Descriptions below are from CNALH: lichenportal.org

I tend to assume the common ones on siliceous rock in Colorado foothills are usually X cumberlandia (esp with its abundant apothecia), but here are a few more:

Flavoparmelia caperata
lower surface black in center, brown at edges; sorediate, no isidia; apothecia rare; rarely on rocks

Thallus: adnate to loosely adnate, foliose, 5-20 cm in diam., sometimes forming extensive patches, irregularly lobate lobes: subirregular, elongate, plane to subconvex, separate, 5-13 mm wide, contiguous to somewhat imbricate; apices rotund, crenate, eciliate upper surface: yellow green to pale yellow, occasionally green-gray (in shade), smooth but becoming rugose and folded with age, dull to somewhat shiny; epruinose and emaculate soredia: laminal, granular to wart-like, initially in circular soralia but becoming diffuse and confluent; isidia: absent medulla: white with continuous algal layer lower surface: black centrally, brown and naked peripherally; rhizines: dense to sparse centrally to edge of brown zone, black, simple, sometime brown or white tipped Apothecia: rare, up to 8 mm wide, laminal, sessile; disc: brown; margin: smooth but sorediate sometimes asci: clavate, 8-spored ascospores: simple, ellipsoid, hyaline, 15-24 x 8-13 µm Pycnidia: laminal, immersed conidia: weakly bifusiform, 6 x 1 µm Spot tests: upper cortex K-, C-, KC+ yellow, P-; medulla K-, C-, KC-, P+ red
Substrate and ecology: on broad leafed trees, shrubs and fence posts in open habitats, coastal to montane up to 2000m, rarely on rocks
World distribution: North and South America, Europe, Asia, Africa

Flavoparmelia baltimorensis:
lower surface black or dark, rhizinate; isidioid pustulae; apo rare

Thallus: adnate to loosely adnate, foliose, 6-15 cm in diam., often fusing to cover large areas, irregularly lobate lobes: sublinear to irregular, elongate, plane to subconvex, separate, 3-8 mm wide; apices: subrotund, crenate, eciliate upper surface: yellow-green, smooth but becoming rugose with age, dull to somewhat shiny, epruinose and emaculate pustulae: abundant, laminal crateriform, isidioid, breaking open apically but not sorediate; true isidia and soredia absent medulla: white with continuous algal layer lower surface: black centrally and toward margin, narrow brown zone peripherally, smooth to papillate; rhizines: sparse to moderately abundant, black, simple Apothecia: rare, laminal on thallus, sessile, 1-4 mm wide; disc: brown; margin: pustulate, pruina and soredia absent asci: clavate, 8-spored ascospores: simple, ellipsoid, hyaline, 13-15 x 6-7 µm Spot tests: upper cortex K-, C-, KC+ yellow, P-; medulla K-, C+ red, KC+ red, P+ red Secondary metabolites: upper cortex with usnic acid; medulla with protocetraric acid (major) and gyrophoric acid (minor to accessory). Substrate and ecology: commonly on acidic rock, rarely tree bases World distribution: eastern and SW North America

Xanthoparmelia cumberlandia
lower surface pale brown to brown; no soredia or isidia; apothecia common

Thallus: foliose, adnate, 6-12 cm in diam., irregularly lobate lobes: primarily subirregular, less often sublinear, elongate, plane, 0.1-0.5 mm wide, separate, usually continguous, less often partially imbricate, 1-2 mm wide, sometimes becoming lobulate centrally lobulae: flat, entire, often branched; apices: subrotund, smooth to crenate, eciliate upper surface: yellow-green to sometimes bluish green, smooth, shiny, epruinose and emaculate, without isidia, soralia or pustulae medulla: white, with continuous algal layer lower surface: pale brown or brown, plane, moderately rhizinate; rhizines: pale brown, simple, 0.3-0.8 mm long Apothecia: common, substipitate, 2-10 mm wide, laminal on thallus; disc: cinnamon-brown to dark brown; margin:smooth, pruina absent asci: clavate, 8-spored ascospores: hyaline, simple, ellipsoid, 9-10 x 4-5 µm Pycnidia: common, immersed conidia: bifusiform, 5-7 x 0.5 µm Spot tests: upper cortex K+ yellow to orange, C-, KC-, P+ orange; medulla K+ yellow becoming dark red, C-, KC-, P+ orange Secondary metabolites: upper cortex with usnic acid (major); medulla with stictic acid (major) and constictic and norstictic acids (both minor) and connorstictic, cryptostictic and peristictic acids (all trace). Substrate and ecology: usually on acidic rocks but in coastal areas on soil and/or pebbles as well, often in open or partially shaded habitats World distribution: Europe, North and South America

Xanthoparmelia lineola:
lower surface pale to med brown, rhizinate; no soredia or isidia; apo common

Thallus: foliose, adnate, 4-20 cm in diam., irregularly lobate lobes: subirregular, elongate, plane to subconvex, separate and contiguous, 0.8-3 mm wide, not lobulate; apices: subrotund, smooth to crenate, eciliate upper surface: yellow to yellow-green, smooth but becoming strongly rugose with age, dull to slightly shiny, epruinose and emaculate, without soralia, isidia, or pustulae medulla: white, with continuous algal layer lower surface: pale to medium brown, plane, moderately rhizinate; rhizines: brown, simple, 0.2-0.4 mm long Apothecia: common, substipitate, 2-5 mm wide, laminal on thallus; disc: cinnamon-brown to dark brown; margin: smooth, pruina absent asci: clavate, 8-spored ascospores: hyaline, simple, ellipsoid, 9-12 x 6-7 µm Pycnidia: common, immersed conidia: bifusiform, 6-7 x 1 µm Spot tests: upper cortex K-, C-, KC-, P-; medulla K+ yellow becoming dark red, C-, KC-, P+ red Secondary metabolites: upper cortex with usnic acid (major); medulla with salazinic acid (major) and consalazinic acid (minor) and often with norstictic and protocetraric acids (both trace). Substrate and ecology: on acidic rocks, often in open or partially shaded habitats World distribution: Australasia, southern Africa and North and South America

Xanthoparmelia conspersa: (X plittii is similar)
lower surface black; apo rare; densely isidiate

Thallus: foliose, adnate to loosely adnate, 4-12 cm in diam., irregularly lobate lobes: subirregular, elongate, plane to subconvex, often black rimmed, separate, contiguous to somewhat imbricate, (0.5-)1-3 mm wide, rarely lobulate; apices: subrotund to subtruncate, smooth to crenate, eciliate upper surface: yellow-green, smooth, shiny, epruinose and emaculate, moderately to densely isidiate isidia: initially globose, soon becoming cylindrical, simple to coralloid branched, 0.06-0.2 mm in diam., 0.1-1 mm tall; tips: syncorticate, dull brown to black; soralia and pustulae absent medulla: white, with continuous algal layer lower surface: black, plane, moderately to densely rhizinate; rhizines: black, simple to furcate, 0.2-0.6 mm long Apothecia: rare, substipitate, 2-8 mm wide, laminal on thallus; disc: cinnamon-brown to dark brown, epruinose; margin isidiate asci: clavate, 8-spored ascospores: hyaline, simple, ellipsoid, 9-10 x 5-6 µm Pycnidia: rare, immersed conidia: bifusiform, 6-7 x 1 µm Spot tests: upper cortex K-, C-, KC-, P-; medulla K+ yellow to orange, C-, KC-, P+ orange Secondary metabolites: upper cortex with usnic acid (major); medulla with stictic acid (major), constictic, cryptostictic and norstictic acids (all minor), connorstictic acid (trace), and sometimes hyposalazinic acid (trace). Substrate and ecology: on acidic rocks, rarely on wood, often in open, arid habitats but also in more shaded, forested habitats World distribution: Europe, Africa, North and South America

Xanthoparmelia novomexicana
lower surface pale to med brown, rhizinate; upper becoming rugose but no soredia or isidia; apo common

Thallus: foliose, moderately to loosely adnate, (2-)4-20 cm in diam., irregularly lobate lobes: subirregular to sublinear, elongate, plane to subconvex, separate and contiguous, 0.8-3 mm wide, not lobulate; apices: subrotund to subtruncate, smooth to crenate, eciliate upper surface: yellow to yellow-green, smooth but becoming strongly rugose with age, dull to slightly shiny, epruinose and emaculate, without soralia, isidia, or pustulae medulla: white, with continuous algal layer lower surface: pale to medium brown, plane, moderately rhizinate; rhizines: pale brown, simple, 0.1-0.3 mm long Apothecia: common, substipitate, 2-5 mm wide, laminal on thallus; disc: cinnamon-brown to dark brown; margin: smooth, pruina absent asci: clavate, 8-spored ascospores: hyaline, simple, ellipsoid, 10-11 x 4-5 µm Pycnidia: common, immersed conidia: bifusiform, 5-6 x 1 µm Spot tests: upper cortex K-, C-, KC-, P-; medulla K-, C-, KC-, P+ red Secondary metabolites: upper cortex with usnic acid (major); medulla with fumarprotocetraric acid (major), protocetraric acid (minor), confumarprotocetraric acid (minor), ±caperatic acid (major), ±norcaperatic acid (minor). Substrate and ecology: on acidic rocks, often in open or partially shaded habitats World distribution: montane areas of western North America extending south to Veracruz

Posted on January 20, 2019 02:45 PM by slwhiteco slwhiteco

Comments

Wow, I feel like Alice down the lichen rabbit hole! So long as none of the chemistry tests involve mercury, I'll avoid a terrible fate as the "Mad Lichener." Did you ever try doing chemical tests on lichens?

Posted by thecaiman1 about 5 years ago

Only when I took lichenology and a bit of work in it thereafter for my prof. That's in the Way Back. What I remember is: K is potassium (chloride?), C is clorox or some such, and P is a really nasty chemical whose name I've forgotten and it's not easily available anyway. KC is using K then C.

The challenge for all this IDing we're doing based on photos is that chemistry is really important in distinguishing species within Xanthos, Cladonias, and undoubtably several others. Also, I'm wondering how people just jump to Flavoparmelia when it's on rocks and looks like Xanthos to me.

Hey, I'm working up a crib sheet on Colorado Usneas-- it's another one that bugs me (everything with apo seems to be pegged to U strigosa here on iNat), and I know there are (or were) others. U strigosa doesn't even seem to be in Colorado. I'll put it in another post and send you the link.

Posted by slwhiteco about 5 years ago

Here's another deep dive down the rabbit hole. Had a lovely morning in lichen land!! Alice is a favorite of mine... what with believing 6 impossible things before breakfast and all...

https://www.inaturalist.org/journal/slwhiteco/21121-colorado-usneas

Enjoy!!

Sally

Posted by slwhiteco about 5 years ago

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