Telling a moss from a lichen or liverwort is one thing; naming the actual species is another, and it is where a lot of people stall. You do not need a laboratory, but you do need a hand lens and a few habits.
Get a hand lens
A simple folding lens at ten or twenty times magnification is far and away the most useful tool, and it changes everything. Mosses are small and the features that separate species, the shape of a leaf, whether it has a midrib, the form of the little capsule, are simply invisible to the naked eye. Hold the lens close to your eye and bring the moss up to it, in good light.
The features that matter
- Growth form: does it grow in upright tufts and cushions (acrocarps) or trailing, branching mats (pleurocarps)? This first split narrows things enormously.
- Leaf shape and arrangement: long and narrow, oval, pointed, blunt, swept to one side, spirally arranged or in ranks.
- The midrib (nerve): a single vein running up the leaf, present or absent, single or double, reaching the tip or stopping short.
- The capsule: upright or nodding, round or cylindrical, on a long or short stalk, with what kind of lid. When present, capsules are full of clues.
Use a key and record it
With those observations you can work through a moss field guide or key, which leads you by yes-or-no questions to a name. Photograph your finds, note where and on what they grew, and consider logging them with a recording scheme or a naturalist app; verified records are genuinely useful to science, and the feedback sharpens your eye. Start with the common species on the species page and build from there.