Botrychium lunaria is a species of fern known by the common name moonwort or common moonwort. It is the most widely distributed moonwort, growing throughout the Northern Hemisphere across Eurasia and from Alaska to Greenland, as well as parts of the Southern Hemisphere including South America and Australia.This is a small plant growing from an underground caudex and sending one fleshy, dark green leaf above the surface of the ground.