Asplenium scolopendrium Cristatum Group - Hart's Tongue Fern

Asplenium scolopendrium 'Cristatum Group', also known as Hart's Tongue Fern, is undoubtedly the most curly-leaved horticultural form of the species. Resembling a beautiful light green curly lettuce, it unfurls its evergreen fronds in dense tufts in shady areas. Its foliage can capture and reflect even the pale rays of winter sun, casting a light on the garden during a time of year devoid of blooms. It is an ideal variety for cold and damp areas of the garden, exposed to the north.

The Hart's Tongue Fern is a perennial fern belonging to the Asplenium family, native to North America, Europe, and Asia. It can be found growing on limestone soils in shaded mountain slopes, ravines, scree, or along watercourses at altitudes below 1800 m (5900 ft), and even inside old wells or in the remains of shaded buildings. The Hart's Tongue Fern is locally protected. Its vernacular name of "Hart's Tongue," is due to the resemblance of its long ribbon-like fronds to the tongue of a deer.

Anchored by a short and thick rhizome covered in reddish-brown scales, Asplenium scolopendrium 'Cristatum Group' forms a clump that reaches a height and width of about 40 cm (16 in) and persists throughout winter. Its fronds, shorter than those of the type species, also have particularly intense undulations along the edges. They are divided and laciniate at their tips, giving them a tousled and frizzy appearance. They are carried by brown and villous petioles that bear dark, brown to black scales at the base. The reproductive cells (sori) are arranged on the undersides of the fronds: they are large, linear, parallel to each other, and oriented obliquely to the rachis; they resemble a type of centipede, which gave the plant its evocative name of scolopendrium.

Asplenium scolopendrium and its cultivars are superb evergreen ferns for rockeries or slopes, under the canopy of trees, in shaded borders, but always in well-drained soil. The 'Cristatum Group' variety is a peculiar fern that easily establishes itself in a few centimetres (about an inch) of compost, clinging between the stones of a rocky scree bordering a small waterfall. But its luminous foliage makes it even more precious in winter, when it covers a wall of old mossy stones, lines the inside of an ancient well, or cascades down a terrace. It thrives alongside ivies, periwinkles, brunneras, lamiums, and the humble Petasites fragrans, which accompany it with fragrance, foliage, or delicate blooms, in stark contrast to its luxuriance. It also forms a beautiful combination with Athyrium niponicum 'Metallicum'.