C. rivularis of Michigan Flora.

Wet sandy or muddy, often marshy shores and banks of streams, ponds, and lakes; wet marshy hollows, wet fields, and wet meadows; ditches and swales. One of our most common smaller species, sometimes weedy in moist soils on trails and along  two track roads. 

This species is highly variable in the amount of reddish-brown tinting on the scales; sometimes these virtually all green.