Cooksonia is one of the first recognized vascular plants. That means it had a system that allowed water and nutrients to be distributed internally. This is an important step for a plant if you are going to exist outside of a watery environment. The specimens below are individual pieces of what could be C. hemisphaerica likely before they fully produced their sporangia.
All three specimens came from the Bertie formation (upper Silurian, Pridoli stage) in Ridgemont quarry, Fort Erie, Ontario, Canada.