Identification notes
The combination of characteristic appearance (blue-green leaves, reddish stem) and habitat (often damp tracks) means that P. wahlenbergii is usually a straightforward plant to identify.
Beware juvenile or small Philonotis fontana though – it often looks very similar and will sometimes grow in the same places. In areas where both species are likely to be found, a quick check of leaves under the microscope should reveal the following characters:
- Leaf bases: Slightly decurrent (P. wahlenbergii) vs. not decurrent (Philonotis);
- Leaf margins: plane, denticulate above, teeth single (P. wahlenbergii) vs. recurved below, toothed from leaf base to apex, some teeth usually double (Philonotis);
- Leaf cells: smooth (P. wahlenbergii) vs. mamillose (Philonotis) – this character can be difficult to see and is often restricted to a few upper or lower cells;
- Nerve: narrow (P. wahlenbergii) vs. robust (Philonotis).
Species varieties
- Pohlia wahlenbergii var. wahlenbergii
- Pohlia wahlenbergii var. glacialis
- Pohlia wahlenbergii var. calcarea
