Was the Calamite the first tree like plant to grow on land? Many scientists believe so. It grew as high as 100 feet, towering above its counterparts in the earlier period of its long lifespan which began during the Devonian Period some 400 million years ago. The trunk was a woody hollow tube lacking true bark, like modern trees. The leaves were primitive and needle like, arranged in whorls. The Calamite thrived in hot swampy tropics, especially during the Pennsylvanian Period around 300 mya. Many of their fossils are found worldwide including, USA, China, Canada, South America and Europe. These fossils were found in Sebastian County, Arkansas in an old coal strip mine in 1993 by Michael A. Whitkanack who donated them to my classroom. They are actually the imprints of the Calamite’s leafs and stems which scientists refer to as trace fossils.
Scientific Name: Calamite Common Name: Horsetail / Wiskfern
Division: Pteridophyta (Ferns, reproduce by spores)
Class: Sphenopsida or Equisetopsida (means ribbed, vertical jointed stem; bamboo like in appearance)
Genus: (STEM) Calamite (LEAF) Annularia
Special Note: The Calamine may look familiar to some as there modern descendants are horsetails growing only a few feet tall in open fields and edges of wooded areas.
Equisetum is a living fossil as it is the only living genus of the entire class of Equisetopsida, which for over one hundred million years was much more diverse and dominated the understory of the late Paleozoic forests. They were related to the Calamites of which decomposed into layers upon layers buried in abundance in coal deposits from the Carboniferous period.