then in 1968 T.J. Koponen separated them into different groups:
1) Leaf margin entire (or obscurely toothed): Pseudobryum, Cyrtomnium & Rhizomnium
2) Leaf margins with single teeth: Plagiomnium
3) Leaf margins with double teeth: Mnium
Let's take a look at the first group:
Rhizomniums are fairly common in our area, especially R. punctatum and R. appalachianum
Both species have leaves that have a strong border of long cells with interior cells that are roundish.
R. punctatum is much smaller than R. appalachianum and i find it most often on rocks in wet areas whereas R. appalachianum grows in wet, swampy soil.
|R. punctatum - note the smooth stems|
Rhizomnium punctatum also has no tomentum or brownish hairs growing up the stem; only at the base.
|a nice clump of Rhizomnium appalachianum|
|a scan of R. appalachianum. notice how the stem is covered with brown 'stuff' covering the stem.|
|Pseudobryum cinclidiodes, compare the leaf shape to R. appalachianum|