There are somewhere between 40 and 50 recognized species of Ptychomitrium, spanning much of the world. According to the Flora of North America, Ptychomitrium incurvum is native to eastern USA, Europe, and Ecuador. Incurved grizzled moss is also designated as extirpated in Canada.
Its former presence in Canada is based on a single documented collection from 1828, near Niagara Falls, Ontario. I do wonder why it hasn’t been rediscovered in nearly two centuries, as the habitat requirements for the species aren’t strict:
[Incurved grizzled moss] grows in the eastern deciduous forest, on both calcareous (containing calcium carbonate) and non-calcareous rocks. It is commonly found on the surface, and in small crevices, of boulders in open hardwood forests. It is occasionally observed at the base of trees or on logs. Incurved Grizzled Moss also frequently becomes established on man-made structures such as rock walls and gravestones.
The Flora of North America account for the genus explains the derivation of Ptychomitrium: “[Greek ptyx, fold, and mitra, turban, alluding to plicate calyptra]”, i.e., the covering on the head of the spore-bearing stalks has folds. These are evident if you expand Robert’s photo.