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Aspicilia heteroplaca (Zahlbr.) Oksner
Family: Megasporaceae
[Lecanora heteroplaca Zahlbr.]
Aspicilia heteroplaca image
Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus yellowish-ashy or paler to clay-colorcd, for the greater part thin, to 1.5 mm thick, continuous, or rarely, minutely and thinly chinky-areolate, the areolae to 0.2 mm broad, flat to convex, scattered over this arc larger, thicker areolae to 1 mm broad, whiter, with subparaplectenchymatous cortex. Apothecia in the raised, larger areolae or over the thin, basal thallus, sessile, constricted at base; margins white to smoky; thalloid margin thin, pale, 1+ pale blue; disk black, dull, bare, concave to flat; hypothecium hyaline; hymenium 90-100 µm, hyaline, 1+ blue, quickly browning; paraphyses very coherent, slender, simple or slightly branched, not moniliform; spores 8, containing large oil droplets, ellipsoid, 15-21 x 11-12 µm. Conidia filiform, straight or curved, 15-18 x 1 µm.

Reactions: K-, C-, P-, I-.

This species grows on calcareous rocks. It is very rare, being known from Novaya Zemlya, Bear Island. Alaska, and the Northwest Territories.