Sigillaria is the generic name assigned to this ancient arborescent lycopod.

It had leaves and roots very similar to its contemporaneous cousin, lepidodendron, but it differed in that it exhibited much rarer branching and its tall, columnar trunk lacked the scale-pattern of lepidodendron, instead exhibiting straight, fluted furrows along the trunk midsection. Occasionally the trunks were smooth.

Other differences with lepidodendron were its cones. Lepidodendron cones were attached individually near the tip of it's branches. Sigillaria cones occurred in clusters attached in certain places along the upper stem.

Another characteristic of sigillaria are the verticallyarranged circular scar pattern found in fossil specimens representing the inner bark. These scars called parichnosoccur in specimens assigned the formgenus name of Syringodendron.

Sigillaria was prolific during the Carboniferous Period (360 to 286 million years ago) and, like its cousin lepidodendron, often attained heights of over 130 feet.

Lepidodendron is the name assigned to this ancient lycopod, also known as the "scale tree" because of the distinctive diamond-shaped leaf scars that covered it's outer bark midsection.

It was prolific during the Carboniferous Period (360 to 286 million years ago) and capable of achieving gigantic size, growing to heights of more than 130 feet with supporting trunks measuring up to 6 feet or more in diameter.