Wiktionary
water horsetail
n. A plant in the taxonomic genus ''Equisetum'' (horsetails); (taxlink Equisetum fluviatile species noshow=1) or (taxlink Equisetum limosum species noshow=1).
WordNet
water horsetail
n. Eurasia; northern North America to Virginia [syn: swamp horsetail, Equisetum fluviatile]