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Aspicilia subradians (Nyl.) Hue (redirected from: Aspicilia subradiascens)
Family: Megasporaceae
[Aspicilia stygioplaca (Nyl.) Hue,  more]
Aspicilia subradians image
Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus olive-black to black, shining, only indistinctly radiate at margin, mostly not; areolate, the areolae very convex or flat; cortex of more or less perpendicular cell rows, paraplectenchymatous; over a black hypothallus. Apothecia sparse, margin thick, of same color as thallus, I-; usually shining; disk black, bare, concave to flat, rough-appearing; hypothecium pale, 1+ blue; epihymenium dark olive-green or brown, HNO,+ green; hymenium 100-150 µm, pale, 1+ blue; paraphyses distinct, not moniliform, sparsely branched, anastomosing with the cells elongated and constricted between; spores 8, ellipsoid, 17-25 x 10-15 µm. Conidia 13-24 µm.

Reactions: medulla K+ yellow turning red and precipitating red needle crystals (must be observed in sections), 1-.

Contents: norstictic acid (my report of salazinic acid (1979) is incorrect).

This species grows on granitic rocks. It is a member of the Bcringian element in the flora, being reported from Siberia, Alaska, and the Northwest Territories.

As already mentioned by Magnusson (1939), Nylander did not observe the color reactions in sections carefully, and he separated the three species in the synonymy above on the reactions. A check of the types uncovered the errors, and the earliest name must be adopted for this species.