any of several terrestrial ferns of the genus Ophioglossum, esp O. vulgatum, that grow in the N hemisphere and have a spore-bearing body that sticks out like a spike from the leaf: family Ophioglossaceae
2. another name for dogtooth violet
adder's-tongue in American English
(ˈædərzˌtʌŋ)
noun
1. US
dogtooth violet
2.
any of a genus (Ophioglossum, family Ophioglossaceae) of ferns with a narrow spike somewhat resembling a snake's tongue