Key to some of the common species
1. Leaf margins irregularly and coarsely toothed … 2.
1. Leaf margins regularly toothed … 3.
2. Laminal cell papillae over lumen or short projecting; setae variously scabrous … C. ciliata
2. Laminal cell papillae strong, extending distally over adjoining cells above; seta smooth … C. depressa
3 Costa strong, in most leaves merging at the leaf apex and incurved … C. merkelii
3. Costa slender to strong, ending or extending to below the leaf apex (not incurved) … 4.
4. Leaf apices mostly truncate-apiculate; distal laminal cells papillose; seta papillose or smooth below and distally roughened … C. pallidia
4. Leaf apices mostly short-acute, often bluntly so; distal laminal cells smooth; seta smooth … 5.
5. Leaves narrowly oblong-ligulate, mostly 1.2 mm long or longer … C. colombica
5. Leaves ovate to short-oblong, mostly 1 mm long or less …6.
6. Leaves 0.35-0.40 mm wide; costa 2/3-3/4 lamina length; margins serrulate-dentate in distal 1/3 … C. rivularis
6. Leaves ca. 0.25-0.30 mm wide; costa 4/5 lamina length; margins serrulate-dentate in distal 3/4-2/3 … C. tenerrima