Polytrichum commune is the most common moss growing on top of soil in our bark yard. Very large, in our conditions gets to about 15 cm tall, with the sporophytes well over 20 cm. Not much weeds germinate within the dense colonies, which is something that I really like. (Less maintenance for the moss garden)
I hope I'm allowed to share these distribution maps from E-Flora BC showing how uncommon Common Haircap Moss is in North America compared to Awned Haircap Moss or Juniper Haircap Moss. You are very fortunate I think to have Polytrichum commune var. commune growing on your property.
It looks like Polytrichum commune var. commune is quite common in Europe too. Polytrichum commune var. commune