FIELD HORSETAIL, Equisetum
arvense L. 1, fertile or reproductive shoots; 2, sterile
or vegetative shoots; 3, rhizomes. Perennial, reproducing
by spores instead of seeds, and by rhizomes, to which are attached small
tubers. Stems tough and wiry, hollow, jointed, and of two types:
fertile, producing fruiting heads and having large, easily
separable joints, not branched; sterile or vegetative, having
much smaller joints, with lateral branches in whorls around the main stem.
Leaves on sterile stems only, in the form of cup-shaped toothed
sheaths at the joints. Fruiting heads contain masses of tiny pale
greenish spores in small pine-cone-like structure. Found mostly
on wet, sandy, or gravelly soil. It is poisonous to livestock when eaten
in large quantities. There are several species of Equisetum in
the area, all of which can be recognized as horsetails from this illustration.