Here's what Chuck has to say about the species of horsetail growing near him:
Your mystery plant is what I have always known as horsetail, an Equisetum species I believe. The horsetail I know has vertical ridges on the stems, and is very abrasive, I think due to its high silica content. Sometimes it is called "scouring rush" for this property. It's what Jim Long uses in his foot soak for toenail fungus, too. It grows along ditchbanks here like the "gone wild" photo you sent, usually on the shady side of the ditch or in slightly moist sites, where more aggressive grasses predominate. For all I know, there may be hundreds of species of Equisetum. The trouble with common names is that they aren't usually that uniform across geography.
Chuck sent this link for more interesting information on both Eleocharis and Equisetum (horsetail and other interesting common names).