Hypnum cupressiforme is one of the most widespread and common of our mosses and. if you want to get to know mosses (even a little bit!) it pays to get to know this one well so that you can then recognise whether what you are looking at is something different.
The cupressiforme part of the name gives us a clue to identification; formed like a cypress tree leaf. That is all well and good if you know what a cypress tree leaf looks like I suppose! It is difficult to describe with words and so you do need a good illustrated guide to help. Each 'leaf' is a pointed structure which appears to be formed of overlapping segments, a bit like an unopened fir cone perhaps. A hand lens is useful here if you want to take moss identification seriously.
You can find Hypnum cupressiforme in almost all terrestrial habitats. It forms blankets over tree stumps and fallen trunks. It grows on bare soil and grows in amongst grass, especially on lawns. It can grow on rocks and on walls. It can thrive on the acid soils of the heath and the calcareous limestone and chalk of the cliffs and downs. In many ways, this is the plant people think of when they think of masses.There are several subspecies of Hypnum cupressiforme which are, apparently, quite variable but for me that is a step too far!Hypnum cupressiforme: the cypress-leaved moss