Bryaceae. Genus Rhodobryum

1. Plants with 1520 rosette-forming leaves; leaves 3.54.5 mm wide; leaf margins revolute up to 180; costa in cross section with small stereid band and bistratose dorsal epidermis 1. R. roseum

A widespread boreal and hemiboreal species, absent from areas with high calcium content where it is replaced by R. ontariense. Leaf rosette features are helpful in recognizing this species.

Plants with 2535[45] rosette-forming leaves; leaves 2.53.5 mm wide; leaf margins revolute up to 360; costa in cross section with large stereid band and unistratose, dorsal epidermis 2. R. ontariense

A widespread species in Asian Russia, common in the Caucasus and with a scattered distribution in calcareous areas of European Russia. The rosette leaves in R. ontariense are more numerous than those in R. roseum, and this makes its habit quite distinct from that species. Also, the leaves of R. roseum are dark-green, while those of R. ontariense are yellow-green.