Selaginella moellendorffii is a lycophyte that is an important model organism, especially in comparative genomics.
Selaginella moellendorffii is a member of an ancient lineage intermediate between vascular and nonvascular plants that first appear in the fossil record some 400 million years ago. They would later form a dominant part of the world's flora during the Carboniferous era. These lycopsids lack true leaves (having microphylls instead) and roots and thus represent an important node on the plant evolutionary tree. As the closest living relatives to the vascular plants, they are essential to understanding the evolution of plants as a whole. The nuclear genome size is approximately 100 mega base pairs, the smallest genome size found for any plant species. The genome has been sequenced with the mediation of the DOE Joint Genome Institute.[1]