hart's-tongue n 1: tropical American terrestrial fern with leathery lanceolate fronds; sometimes placed in genus Polybotrya [syn: {hart's-tongue fern}, {Olfersia cervina}, {Polybotrya cervina}, {Polybotria cervina}] 2: Eurasian fern with simple lanceolate fronds [syn: {hart's-tongue fern}, {Asplenium scolopendrium}, {Phyllitis scolopendrium}]