Botrychium tunux, newly found in Colorado, was described by Stensvold and Farrar in 2002.  B. tunux is rare in Colorado, but how rare has not yet been determined. This Botrychium was first found and described from Alaska, hence its name "tunux", for a native Alaskan warrior.  B. tunux has recently been found in several western states.

B. tunux has dark glossy green pinnae, is small, only 3-4 inches tall, and it is very similar in shape to Botrychium lunaria. The shape of the pinnae of B. tunux tend to be round; the pinnae of B. lunaria tend to be fan shaped.

The common name for B. tunux, "Moosewort Moonwort", was given because of the split in the basal pinnae of the species making them resemble the antlers of a Moose. The Colorado version of B. tunux seldomly has this basal pinnae feature; the pinnae all tend to be rounded.