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Buellia elegans Poelt
Family: Caliciaceae
Buellia elegans image
Stephen Sharnoff  
Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus of white lobules or radiate lobes, 1-2 cm long, 0.3-1 cm broad; hypothallus lacking; cortex above 20 μm thick, inspersed with crystalline granules; underside pale, attached with fine hyphae. Apothecia at first immersed, soon becoming adnate; the broken-through thallus persisting around the margin; margin thin, black, persistent; exciple dark red-brown; disk black, flat to slightly convex, dull, soon epruinose; hypothecium black-brown to black-gray; hymenium 70-85 μm, hyaline, 1+ blue; paraphyses 1-1.5 μm, tips 4-5 μm and brown; spores brown, 1-septate, slightly constricted, warty when ripe, wall thin, oblong-ellipsoid, 13-22 x 6-10 μm.

Reactions: cortex K+ yellow, C-, P-, UV+ orange; medulla K-, P-, or K+ red, P+ orange-red in spots.

Contents: atranorin in cortex, medulla sometimes with norstictic acid; possibly xanthones in cortex.

This species grows on soil in dry open areas, usually calcareous. It is known from Europe in the Alps, from Afghanistan, and from North America, where it is found in the Great Plains and in the Arctic. North American reports of Buellia epigaea actually represent this species. B. epigaea is not lobate and is K-, lacking atranorin; Poelt reported it as European (Poelt & Sulzer 1974).