Herbarium specimens of Cyrtomnium hymenophylloides document that this calcicole moss is widespread at lowland stations across the North American Arctic, largely north of treeline. It is found southward in the Rocky Mountains of western Canada, often in high elevation vegetation, and in New York-New England-eastern Canada in mountainous areas, but at lower altitudes beneath deciduous or conifer-deciduous forest. Its southeasternmost disjunct stations, which occur north of the glacial boundary, are interpreted as relicts on the basis of a late-Pleistocene fossil recovered from sediment of glacial Lake Hitchcock, southeastern Vermont. Extant
populations occur near where the fossil was found. Spore production is unknown in North America in this dioicous moss, but its fragile stems may allow local dispersal at edaphically favorable sites and over longer distances in treeless vegetation. The southeasternmost disjunct populations may be clones, the persistence of which is favored by vegetative spread through the proliferation of new leafy branches from portions of the plants growing at or below the surface of the soil.