Caloplaca tominii Savicz occurs in Southwestern Yukon (Canada, Region of Kluane), beyond its previous known range (Central Asia, southern Norway, Greenland). The species is epigaeous, strongly basiphytic, xero- and heliophytic. It grows in communities belonging to the Toninion coeruleonigricantis. Its occurrence in the Yukon is allowed by a strongly continental local climate in connection with periglacial phenomena.
