Asplenium scolopendrium

Asplenium scolopendrium
Scientific classification
Kingdom:	Plantae
Division:	Pteridophyta
Class:	Pteridopsida
Order:	Blechnales
Family:	Aspleniaceae
Genus:	Asplenium
Species:	A. scolopendrium
Binomial name
Asplenium scolopendrium L.

Asplenium scolopendrium (syn. Phyllitis scolopendrium, Hart's-tongue Fern) is a fern in the genus Asplenium. The plants are unusual in being ferns with simple, undivided fronds. 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. 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".^[1]

Asplenium scolopendrium is a common species in Europe, 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.^[2] In the United States, A. scolopendrium var. americanum was declared endangered in 1989.^[3] 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.^[2]

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.^{[citation needed]} 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.^[4]

Cultivation and uses

Asplenium scolopendrium is often grown as an ornamental plant, with several cultivars 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.^{[citation needed]}

This fern was recommended in folk medicine as a spleen tonic and for other uses.^[5]

References

1. ^ "Flora Europaea: Asplenium scolopendrium". http://rbg-web2.rbge.org.uk/cgi-bin/nph-readbtree.pl/feout?FAMILY_XREF=&GENUS_XREF=Asplenium+&SPECIES_XREF=scolopendrium&TAXON_NAME_XREF=&RANK=. 
2. ^ ^{a b} "Flora of North America: Asplenium scolopendrium var. americanum". http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233500199. 
3. ^ Currie, Robert R. (September 1993). American hart’s-tongue recovery plan (Report). Atlanta, Georgia: U.S. Fish and Wildlife Service. http://www.fws.gov/northeast/nyfo/es/amhtfrecovplan.pdf. Retrieved 2010-02-28. 
4. ^ Murakami, N.; Nogami, S.; Watanabe, M.; Iwatsuki, K. (1999). "Phylogeny of Aspleniaceae inferred from rbcL nucleotide sequences". American Fern Journal 89: 232–243. doi:10.2307/1547233. JSTOR 1547233. 
5. ^ Hill, John (1812). The family herbal: or An account of all those English plants, which are remarkable for their virtues, and of the drugs which are produced by vegetables of other countries; with their descriptions and their uses, as proved by experience. C. Brightly and T. Kinnersley. p. 162. http://books.google.com/books?id=JgMAAAAAQAAJ&pg=PA162. 

• Hyde, H. A., Wade, A. E., & Harrison, S. G. (1978). Welsh Ferns. National Museum of Wales. ISBN 0-7200-0210-9.

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  Habitat

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  A cultivar with frilled frond margins

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  A specimen growing in lime mortar on a wall.