This small, dark, hoary cushion-former will almost always have to be collected and its leaves sectioned before it will give up its identity.
The margins from the leaf base to the tip become gradually more incurved and the uppermost leaf section is really distinctive, being keeled and resembling a pair of tongs (see gallery). Other useful microscopic characters include transversely rectangular cell lumens and several rows of basal hyaline cells extending up the leaf margin to a row of unusual transversely oval marginal cells at the shoulder. Capsules are rare but are neat-looking on short erect setae. Grimmia montana also lacks stomata on the walls of its capsules so if you immerse them in KOH (to make them more visible) you won’t find any.Read the Field Guide account