ˈ ̷ ̷ ̷ ̷ˌ ̷ ̷ noun
also adder tongue
( plural adder's-tongues also adder tongues )
Etymology: so called from the shape of its fruiting spike
1. : a fern of the genus Ophioglossum
2. : any of several plants especially in the genera Achillea, Arum, Erythronium, Geranium, Orchis, and Peramium having leaves or flower or fruiting spikes suggesting the fruiting spikes of adder's-tongue fern