Definition of adder's tongue in English:

adder's tongue

(US adder-tongue)

noun

  • 1A fern having a single pointed oval frond and a straight spore-bearing stem.

    • ‘Over 103 species of grasses and herbs have been recorded in the meadows including green-winged orchid, common spotted orchid, adder's tongue, pepper-saxifrage, yellow rattle and saw-wort.’
    • ‘Since they sprout from perennial caudices, the adder's tongue ferns were presumably established in the chamise understory.’
    • ‘In it grow such ferns as adder's tongue fern, bog fern, Christmas fern, crested fern, Goldie's fern, maidenhair fern, New York fern, ostrich fern, and spinulose woodfern.’
    • ‘The general conclusion was that the impact of the first year's cattle grazing had helped the adder's tongue fern to thrive.’
    • ‘We have beautiful new note cards depicting fetid adder's tongues, woodland wildflowers, northwest conifers, and Mill Valley lichens.’
  • 2

    North American term for dog's-tooth violet
    • ‘Adder's tongue is a perennial plant that grows to 1 foot high.’