Adder's tongue is a common name for several plants and may refer to:
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Ophioglossum
''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns in the family Ophioglossaceae. The name ''Ophioglossum'' comes from the Greek meaning "snake-tongue". '', a genus of ferns in the family Ophioglossaceae
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Erythronium
''Erythronium'', the fawn lily, trout lily, dog's-tooth violet or adder's tongue, is a genus of Eurasian and North American plants in the lily family, most closely related to tulips. The name Erythronium derives from Ancient Greek () "red" in ...
'' (also known as fawn lily, trout lily, or dog's-tooth violet), a genus of lilies
{{Plant common name