What is "cooksonia"

Cooksonia is an extinct grouping of primitive land plants. The earliest Cooksonia date from the middle of the Silurian (the Wenlock epoch); the group continued to be an important component of the flora until the end of the Early Devonian, a total time span of . While Cooksonia fossils are distributed globally, most type specimens come from Britain, where they were first discovered in 1937. Cooksonia includes the oldest known plant to have a stem with vascular tissue and is thus a transitional form between the primitive non-vascular bryophytes and the vascular plants.

Cooksonia is a genus of butterfly in the family Lycaenidae.Cooksonia is endemic to the Afrotropics.