Two taxa regarded as varieties of Collema tenax by the monographer Gunnar Degelius are shown to be species with distinct characters, including ecogeography.
(1) Enchylium expansum (Degel.) comb. nov., a widespread, shiny, rather Leptogium- like species, is disjunctly circumpolar with outlying single localities in the European Alps (Austria) and the southern Rockies (USA) at high altitudes (ca.3000m), as well as with an interesting single locality on Kerguelen Island in the Southern Hemisphere. (2) Enchylium substellatum (H. Magn.) comb. nov. has characteristically folded thalli with elongated, narrow lobes as well as notably long and narrow, and constantly 3-septate ascospores. It appears to be most common in the Rockies and Northeast Greenland with single localities in inner China (type) and remarkably in the Sierra Nevada, Spain. It appears to prefer open, clay-rich or sandy soils in more or less continental climates with cold winters and warm summers. They are both referred to the genus Enchylium where the Collema tenax group is now placed.