Asplenium scolopendrium, known as hart’s-tongue or hart’s-tongue fern is a fern in the genus Asplenium, of the Northern Hemisphere
The plants are unusual in being ferns with simple, undivided fronds. The tongue-shaped leaves have given rise to the common name “Hart’s tongue fern”; a hart being an adult male red deer. The sori pattern is reminiscent of a centipede’s legs, and scolopendrium is Latin for “centipede”. The leaves are 10–60 cm long and 3–6 cm broad, with sori arranged in rows perpendicular to the rachis.
The plants grow on neutral and lime-rich substrates, including moist soil and damp crevices in old walls, most commonly in shaded situations but occasionally in full sun; plants in full sun are usually stunted and yellowish in color, while those in full shade are dark green and luxuriant. The rare occurrences of the North American form in the southeastern US are found exclusively in sinkhole pits. These populations may be relics of cooler Pleistocene climates.