Field Horsetail, Equisetum arvense
Although they are not ferns, Equisetums are considered one of the oldest of the fern relatives, the descendants of prehistoric treelike plants that lived 300 million years ago.
This species, the most common of the horsetails, seldom grows taller than 2 feet. It can become weedy when growing in moist, semi-shaded areas. Found across the northern hemisphere except in hot climates.