Fast forward to today and these monolith primitive ferns have shrunk significantly, but not much else has changed. Modern horsetail (Equisetum arvense) still thrives in cool, dank wetlands, on the shores of rivers and lakes, and in open grasslands throughout North America and reproduces by spores.
Botanically, horsetail has maintained much of its prehistoric structure with its segmented stalk and whorled leaves, which botanically aren't leaves at all but toothed sheathes that resemble singular pine needles.
Horsetail plant prefers the northern sides of mountains, and areas of forest that provide ample shade. Springs, standing water, and waterways are all likely habitat for this ancient fern, but since horsetail is a native plant to much of the northern hemisphere, it can be found growing in many plant communities including Yellow Pine Forest, Red Fir Forest, Lodgepole Forest, Subalpine Forest, Foothill Woodland, Chaparral, Valley Grassland, and wetland-riparian.