Hart's-tongue fern
Encyclopedia
Asplenium scolopendrium, Hart's-tongue Fern (syn. Phyllitis scolopendrium) is a fern
in the genus Asplenium
, of the Northern Hemisphere.
, but in North America
occurs as rare, widely scattered populations that have been given varietal status, A. scolopendrium var. americanum. Morphological differences are minor, but the North American populations are tetraploid, whereas those occurring in Europe are diploid.
In the United States, A. scolopendrium var. americanum was declared endangered in 1989. The reason that the European variety is relatively widespread, and the American variety a rarity, has apparently not been established. A third variety occurs in Southern Mexico and Hispaniola
, A. scolopendrium var. lindenii.
s. . The tongue-shaped leaves have given rise to the common name "Hart's tongue fern"; hart
is an old word for 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 colour, while those in full shade are dark green and luxuriant
, with several cultivar
s selected with varying frond form, including with frilled frond margins, forked fronds and cristate forms. The American variety is reputed to be difficult to cultivate, and most, if not all, cultivated plants are derived from European forms.
tonic and for other uses.
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
in the genus Asplenium
Asplenium
Asplenium is a genus of about 700 species of ferns, often treated as the only genus in the family Aspleniaceae, though other authors consider Hymenasplenium separate, based on molecular phylogenetic analysis of DNA sequences, a different chromosome count, and structural differences in the rhizomes...
, of the Northern Hemisphere.
Distribution
Asplenium scolopendrium is a common species in EuropeEurope
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, but in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
occurs as rare, widely scattered populations that have been given varietal status, A. scolopendrium var. americanum. Morphological differences are minor, but the North American populations are tetraploid, whereas those occurring in Europe are diploid.
In the United States, A. scolopendrium var. americanum was declared endangered in 1989. The reason that the European variety is relatively widespread, and the American variety a rarity, has apparently not been established. A third variety occurs in Southern Mexico and Hispaniola
Hispaniola
Hispaniola is a major island in the Caribbean, containing the two sovereign states of the Dominican Republic and Haiti. The island is located between the islands of Cuba to the west and Puerto Rico to the east, within the hurricane belt...
, A. scolopendrium var. lindenii.
Description
The plants are unusual in being ferns with simple, undivided frondFrond
The term frond refers to a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group...
s. . The tongue-shaped leaves have given rise to the common name "Hart's tongue fern"; hart
Hart (deer)
The word hart is an old alternative word for "stag" ....
is an old word for deer. The sori
Sorus
A sorus is a cluster of sporangia .In fungi and lichens, the sorus is surrounded by an external layer. In some red algae it may take the form of a depression into the thallus....
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
Rachis
Rachis is a biological term for a main axis or "shaft".-In zoology:In vertebrates a rachis can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the rachis usually form the supporting axis of the body and is then called the spine or vertebral column...
.
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 colour, while those in full shade are dark green and luxuriant
Taxonomy
A. scolopendrium, with its close relative A. sagittatum, has also been placed in a segregate genus Phyllitis. A. scolopendrium forms hybrids with other Asplenium species, including those species sometimes classified in the separate genus Camptosorus, which is one reason that both Phyllitis and Camptosorus species are now generally included in Asplenium. On the other hand, a recent phylogenetic study of the Aspleniaceae family suggests that A. scolopendrium is only distantly related to other Asplenium species, and that the genus Phyllitis should again be recognized.Cultivation
Asplenium scolopendrium is often grown as an ornamental plantOrnamental plant
Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...
, with several cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...
s selected with varying frond form, including with frilled frond margins, forked fronds and cristate forms. The American variety is reputed to be difficult to cultivate, and most, if not all, cultivated plants are derived from European forms.
Medicinal
This fern was recommended as a medicinal plant in folk medicine as a spleenSpleen
The spleen is an organ found in virtually all vertebrate animals with important roles in regard to red blood cells and the immune system. In humans, it is located in the left upper quadrant of the abdomen. It removes old red blood cells and holds a reserve of blood in case of hemorrhagic shock...
tonic and for other uses.