Horsetail

Critter trails through scouring rush on Bull Creek

This time of year when nature lacks color there is an evergreen that doesn't get much press.  It thrives permanently on several banks along Bull Creek but is easy to overlook.  It doesn't flower, has no seeds or leaves, and stands less than three feet tall.  It is an ancient species and definitely a "horse of a different color."   

Equisetum (horsetail) is as primitive as it looks, a genus of living fossils, the only surviving members of its class named Equisetopsida, members of the fern family.  Their heyday was the Paleozoic Era (360-250 million years ago) when they were the dominant plants.  There were many diverse species filling the under story of the forests, some growing 90 feet tall. Their remains have accumulated in the earth for millions of years, producing our coal beds.
 

Jointed stems of Equisetum - John Hilty at Illinoiswildflowers.info

Our species is Equisetum hyemale, a.k.a. scouring rush, so named because of the silica concentrations in its stem.  Native Americans used it for polishing and settlers scoured pans with it.  Modern day craftsmen still use it for fine polishing and clarinetists use it to polish their reeds.  Like almost any living plant, some have touted Equisetum as a medicinal or a wild food although the descriptions of preparation could also probably be applied to serving sandpaper for supper.  ASPCA sources describe its toxicity in horses.  Fortunately, it is a survivor and is likely to outlast these few uses.  It grows aggressively along the water and is considered an invasive species in South Africa and Australia.

 Multiple lateral cones - John Hilty

Spore-bearing cone - John Hilty

Equisetum reproduces primarily by rhizomes which are more numerous than their stems.  They can work their way down 6 feet into the soil and are therefore resistant to pulling.  They also reproduce sexually like ferns by producing spores from a cone at the tip or sometimes several lateral cones.  Once they release their spores in late spring or early summer the cones drop off, much like vascular plants shed their flowers. 

 Black teeth (leaves) - Illinoiswildflowers

It has another virtue appreciated by children.  You can pull them apart and slip them back together like joints on a fly rod.  Each stem is hollow for two-thirds of its diameter with joints every few inches.  The joints have fine longitudinal ridges and with magnification you can see 15 to 40 tiny black teeth on the upper rim that may break off with age.  These are actually leaves!  The stems contain the chlorophyll that produces it energy.

I find the best website for detailed information on Missouri plants is Illinoiswildflowers.  It also is rich in faunal associations and has great photographs, many of which are available to non-profit organizations like ours through their photo use policy.  A big thanks to webmaster John Hilty and his team.