This is a genus of only ten species all of which apart from C. trifida, are exclusively north American.

The species are all saprophytic and depend on mycorrhizal fungus for the majority of their nutrition, they do however  maintain a significant amount of chloraphyll in their their stems and are therefore able to manufacture some of their food via photosynthesis .

This  capability accounts for the greenish colouration of  the plants and in the case of C. trifida, serves to differentiate it from the other European saprophytes which contain no chlorophyll at all.  Unlike these species however, it rarely reproduces vegetatively and relies almost entirely on self pollination.