What did the trunk and leaves of Lepidodendron look like?

Lepidodendron was a tree-sized lycopsid that featured a distinct appearance as it matured:

• Trunk: These plants grew up to 40 meters (130 feet) tall and 2 meters (7 feet) in diameter. The trunk was characterized by a slender central strand of wood surrounded by thick bark. As the plant grew, it shed its leaves, leaving behind a pattern of diamond-shaped leaf bases on the older parts of the stem.1
• Leaves: In the juvenile stage, the plant possessed a shock of long, thin leaves sprouting near the growing tip. Once the plant reached later stages and began to branch, the leaves became shorter and awl-shaped.1