Thompson, J., 1984. American Arctic Lichens: The Macrolichens.
This species is rare, known only from the type specimen from northwest Siberia and a report from Baffin Island, Hale no. 289. S. leprocephalum is reported by Lamb to have a distinguishing content of atranorin plus porphyrilic acid. The Hale specimen however contains lo-baric acid plus the atranorin. The specimen was first determined by Lamb as S. leprocephalum, then in a later annotation as S. coniophyllum and yet apparently retained again in S. leprocephalum in the Lamb 1977 Conspectus. In view of the discrepant chemistry and the confusing annotation I have not accepted this species as being in the American Arctic but have retained it in the key in case of future discovery. It would be more expected in the Alaskan sector than so disjunct in the Canadian eastern Arctic.