Cooksonia

Cooksonia is a prehistoric genus of land plant. Cooksonia dates back to the Middle Silurian, all the way to the Early Devonian.^[1] Most fossils of Cooksonia were found in the United Kingdom in 1937.^[3] Cooksonia is known as the earliest plant with a xylem, and so it is considered to be a transitional fossil between Bryophytes (Mosses and others) and Vascular Plants. ^[4]

Cooksonia Temporal range: Wenlock to Early Devonian[1][2] PreꞒ Ꞓ O S D C P T J K Pg N
Reconstruction of Cooksonia
Scientific classification
Kingdom:	Plantae
Superdivision:	Polysporangiomorpha
Form taxon:	†Cooksonioidea
Genus:	†Cooksonia Lang, 1937
Type species
Cooksonia pertoni Lang, 1937

Only the sporophyte (or spore-bearing) phase of the plant is known, and was only a few centimeters tall. It does not have leaves or roots, though might be rooted through rhizomes.^[2]