ia a perennial that spreads via rhizomes. Its stems are hollow
except at the nodes. They are ridged lengthwise. Sterile green
stems are 1 to 3 feet tall and have many slender, whorled branches.
The sterile stems form in late winter and persist through the
growing season. Fertile, fleshy, brown, unbranched stems are
6 to 18 inches tall and are tipped by cone-like strobili that
produce masses of green spores. The fertile stems are produced
in winter and wither soon afterward. Giant horsetails are found
along streambanks, in ditches, and in seepage areas.