Rufus Ward: The Riverwalk's living fossil

February 9, 2013 8:41:55 PM



Most people pay no attention to the green tubular stalk of a plant that grows along the banks of the Tombigbee River at Columbus' Riverwalk. The plant can also be found in clusters along nature trails at MUW's Plymouth Bluff Center. It is commonly called a horsetail and was here before the dinosaurs. 


The horsetail, technically a type of equisetum, has been around a long time and it's ancestral form helped produce the world's vast coal deposits. It is the only surviving member of a family of plants that has been around for some 400 million years. Horsetails are a vascular plant with ribbed, jointed stems that does not have seeds but reproduces by spores.  


These plants grow in damp places such as stream banks or swampy areas. It was in those types of environments that they first lived and died helping form the extensive coal deposits found across north Alabama. Within those coal deposits of over 300 million years ago are found the fossil remains of a type of horsetail that grew to the size of trees. It is estimated that they reached heights of 40 feet. 


Years ago on a trip to Smith Lake in Walker County, Ala., I found the fossil of an early type of a very large horsetail. The hollow stem of the plant had filled with sand and after millions of years turned into a sandstone internal cast of the stem. Except for being stone and much larger it looks very much like the horsetails found today growing along the banks of the Tombigbee River. The one obvious difference is that while the horsetails along the banks of the Tombigbee are generally three to six-feet high the fossil one came from a plant that was probably well over 30-feet high.  


Another name for the Horsetail is the scouring rush and it has been called "nature's scouring pad." This is because silica is found in the stem, making it almost as abrasive as sandpaper. That feature resulted it being frequently used by early settlers as a scouring pad to clean pots. 


Though poisonous in large quantities to horses and possibly other livestock, horsetails have been a herbal remedy since ancient Greece and Rome. Traditionally it was used to treat tuberculosis, dress wounds and help kidney problems. Even today some claim that horsetails are high in antioxidants. 


In Japan young plants are cooked and eaten like asparagus. Dried and ground the plant has been used both as a thickening agent and to make a tea. It can also be used to make a green dye. The plant has been found to be dangerous when eaten by people with some medical conditions so it is not safe for those not very familiar with its properties to eat it. This living fossil has a long and interesting history having survived for 400 million years. In walking along the trails at Plymouth Bluff or along the Riverwalk it is fascinating to see a plant relatively unchanged except for size since before the age of dinosaurs.