Description ²

 Life habit: lichenized; Thallus: small foliose, circular to irregular in outline, often forming rosettes, sometimes irregularly coalescing and spreading over its substrate, loosely adnate to adnate, lobate; lobes: usually flat to convex but sometimes subterete, discrete, often loosely imbricate, elongate; apices: horizontal, sometimes ascending or semierect to erect, eciliate; upper surface: lemon yellow to mustard yellow but in shade paling to yellow-green, dull to somewhat shiny, with or without pruina, with or without isidia or soredia; upper cortex: paraplectenchymatous; medulla: white, reticulate; photobiont: primary one a chlorococcoid alga, secondary photobiont absent; lower cortex: paraplectenchymatous, sometimes lacking; lower surface: white to yellow, smooth to somewhat wrinkled, often rhizinate but sometimes with hapters; rhizines: simple or or sparingly branched; Ascomata: apothecial, lecanorine, laminal, sessile; margin: concolorous with the thallus, persistent, smooth or sorediate or lobulate; disc: darker yellow than the thallus; epithecium: yellow-brown, granular; hymenium: colorless below, I+ blue; paraphyses: simple or sparingly branched, cylindrical or submoniliform, sometimes anastomosing below, septate; hypothecium: colorless to pale brown; asci: clavate, Candelaria-type (apical dome I+ blue only in the lower part), 8-64+-spored; ascospores: usually ellipsoid, simple to thinly 1-septate, uni- or biguttulate or with numerous oil-droplets, colorless; Conidiomata: pycnidial, more or less globular, concolorous with the thallus or darker (walls pale), usually appearing as raised warts on thallus surface; conidia: ellipsoid to narrowly ellipsoid, simple, colorless; Secondary metabolites: pulvinic acid derivatives present in colored parts; Geography: world-wide; Substrate: common on rocks or bark, rarely on soil or mosses. 

Sources and Credits

1. (c) Jason Hollinger, some rights reserved (CC BY-SA), https://images.mushroomobserver.org/640/242168.jpg
2. (c) Lichen Unlimited: Arizona State University, Tempe., some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/10547304

More Info

• iNat taxon page
• Biodiversity Heritage Library
• BOLD Systems BIN search
• Global Biodiversity Information Facility (GBIF)
• Mushroom Observer
• SEINet Symbiota portals

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