swamp horsetail: Eurasia; northern North America to Virginia
horsetail: perennial rushlike flowerless herbs with jointed hollow stems and narrow toothlike leaves that spread by creeping rhizomes; tend to become weedy; common in northern hemisphere; some in Africa and South America
eagle ray: powerful free-swimming tropical ray noted for `soaring' by flapping winglike fins; usually harmless but has venomous tissue near base of the tail as in stingrays