Ptilium crista-castrensis is a moss species within the family Hypnaceae, in the class Bryopsida, subclass Bryidae and order Hypnales.
This species occurs on the floor of Canadian boreal forests as well as many forests of northern Europe; an example of this occurrence is within the Black Spruce/Feathermoss climax forest, often having moderately dense canopy and featuring a forest floor of feathermosses including Hylocomium splendens, Pleurozium schreberi and Ptilium crista-castrensis.
- ^ ITIS Report. 1999
- ^ C. Michael Hogan. 2008