Sigillaria
From Wikipedia, the free encyclopedia
Sigillaria is the name of a genus of extinct, spore-bearing, arborescent (tree-like) plants which flourished in the early Carboniferous period. Sigillaria was most common in the Carboniferous, but dwindled to extinction in the early Permian period. It was a lycopod, and is related to the lycopsids, or club-mosses, as was its associate Lepidodendron.
Sigillaria was a tree-like plant, with a tall, occasionally forked trunk that lacked wood. Support came from a layer of closely packed leaf bases just below the surface of the trunk, while the center was filled with pith. The old leaf bases expanded as the trunk grew in width, and left a diamond-shaped pattern, which is evident in fossils. The trunk had photosynthetic tissue on the surface, meaning that the trunk probably appeared green instead of brown.
The trunk of Sigillaria was topped with a plume of long, grass-like, microphyllous leaves, so that the plant looked somewhat like a tall, forked bottlebrush. The plant bore its spores (not seeds) in cone-like structures attached to the stem. Sigillaria, like many ancient lycopods, had a relatively short life cycle - growing rapidly and reaching maturity in a few years.
Some have suggested that Sigillaria was monocarpic, meaning that it died after reproduction, though this has yet to be proven. It was associated with Lepidodendron, the scale tree, in the Carboniferous coal swamps.
