Adiantum aleuticum

Western maidenhair fern
	Western maidenhair (Adiantum aleuticum)
Conservation status
	; Secure (NatureServe)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Division:	Polypodiophyta
Class:	Polypodiopsida
Order:	Polypodiales
Family:	Pteridaceae
Genus:	Adiantum
Species:	A. aleuticum
Binomial name
	Adiantum aleuticum; (Rupr.) C.A.Paris
Subspecies
	Adiantum aleuticum subsp. aleuticum; Adiantum aleuticum subsp. subpumilum (W.H.Wagner) Lellinger;
Synonyms
	Adiantum pedatum L. subsp. aleuticum (Rupr.) Piper & Beattie; Adiantum pedatum L. subsp. aleuticum (Rupr.) Calder & Roy L.Taylor, nom. illeg. superfl.; Adiantum pedatum L. var. aleuticum Rupr.; Adiantum pedatum L. subsp. calderi Cody; Adiantum pedatum L. var. praeflexum Copel. ex C.F.Baker, nom. nud.; Adiantum pedatum L. var. rangiferinum E.S.Burgess;

Adiantum aleuticum, the western maidenhair fern or Aleutian maidenhair, is a species of deciduous fern in the genus Adiantum.

Description

A. aleuticum typically grows about 18-30 inches tall and wide.^[1] The fronds grow 6–10 in (15–25 cm) tall,^[2] and are fan-shaped, light to medium green with dark brown to black stems.^[3] When growing in relative shade, fronds are held horizontally, but it also can grow in high mountains in full sun (often on serpentine rock) with fronds held vertically. New fronds unfurl from a tight coil (circinate vernation) held on a tall stalk. Oblong sori (masses of spores) form beneath a curled-under leaflet edge (false indusium).^[2]

Tilden Regional Park California
growing on serpentine rock
new fronds unfolding

Taxonomy

Formerly classified as A. pedatum var. aleuticum, it was shown to be a separate species in 1991.^[4]^[5]

Other common names include serpentine maidenhair and five-fingered fern.

Distribution and habitat

Adiantum aleuticum is native mainly to western North America from the Aleutian Islands of Alaska, south to Chihuahua, and also locally in northeastern North America from Newfoundland south to Vermont.^[6] It prefers fertile, moist soil in rock crevices near streams, from sea level in the north of its range, up to 3,200 m altitude in the south of its range. It tolerates serpentinite rock well, and is confined to this mineral-rich rock in some areas.^[6] When growing on sunny serpentine talus and bedrock, the fronds are held vertically, giving the fern a rather different general appearance.^[7]

Cultivation

The species^[8] and its cultivar 'Subpumilum' have gained the Royal Horticultural Society's Award of Garden Merit.^[9] Though hardy they may also be grown as houseplants. They prefer low to medium light, and will grow in moist potting mix. They may prove difficult to keep alive in dry climates.^[10]

Etymology

Adiantum is derived from Greek and means 'unwetted'. This name is in reference to the fact that its leaves do not become saturated, even when they are submerged in water.^[11] In the US, they are suitable for USDA hardiness zones 3–8.^[1]

Aleuticum means 'from the Aleutian Islands'.^[11]

Cultivars

Cultivars include:

'Japonicum'^[12]
'Imbricatum'^[13]
'Subpumilum'^[9]

References

^ ^a ^b "Adiantum aleuticum (Maidenhair Fern)". Gardenia.net. Retrieved 2021-03-31.
^ ^a ^b habitatdana (26 November 2018). "Western Maidenhair Fern, Adiantum aleuticum". Native Plants PNW. Retrieved 2021-03-31.
^ "Adiantum aleuticum". Hardy Fern Foundation. 2018-04-30. Retrieved 2021-03-31.
^ Paris, Cathy A. (April 1991). "Adiantum viridimontanum, a new maidenhair fern in eastern North America". Rhodora. 93 (874): 105–121. JSTOR 23312786.
^ Flora of North America Editorial Committee (ed.). "Adiantum aleuticum". Flora of North America North of Mexico (FNA). New York and Oxford: Oxford University Press – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
^ ^a ^b "Adiantum aleuticum". Jepson Herbarium, University of California. Retrieved 14 September 2019.
^ Hitchcock, C.L. and Cronquist, A. 2018. Flora of the Pacific Northwest, 2nd Edition, p. 55. University of Washington Press, Seattle.
^ "Adiantum aleuticum". Royal Horticultural Society. Retrieved 2 January 2018.
^ ^a ^b "RHS Plant Selector - Adiantum aleuticum 'Subpumilum'". Retrieved 23 February 2020.
^ Hoshizaki, Barbara Joe; Moran, Robbin C. (2001). Fern Grower's Manual. Portland, Oregon: Timber Press. p. 160. ISBN 9780881924954.
^ ^a ^b Gledhill, David (2008). "The Names of Plants". Cambridge University Press. ISBN 9780521866453 (hardback), ISBN 9780521685535 (paperback). pp 36, 42
^ "Adiantum aleuticum 'Japonicum'". BBC Gardeners' World Magazine. Retrieved 2021-03-31.
^ "Buy five-fingered maidenhair fern ( syn. Adiantum pedatum ) Adiantum aleuticum 'Imbricatum'". www.rhsplants.co.uk. Retrieved 2021-03-31.

External links

[:0-1] "Adiantum aleuticum (Maidenhair Fern)". Gardenia.net. Retrieved 2021-03-31.

[:1-2] tatdana (26 November 2018). "Western Maidenhair Fern, Adiantum aleuticum". Native Plants PNW. Retrieved 2021-03-31.

[3] "Adiantum aleuticum". Hardy Fern Foundation. 2018-04-30. Retrieved 2021-03-31.

[4] Paris, Cathy A. (April 1991). "Adiantum viridimontanum, a new maidenhair fern in eastern North America". Rhodora. 93 (874): 105–121. JSTOR 23312786.

[EFLO-5] Flora of North America Editorial Committee (ed.). "Adiantum aleuticum". Flora of North America North of Mexico (FNA). New York and Oxford: Oxford University Press – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.

[JEPS-6] "Adiantum aleuticum". Jepson Herbarium, University of California. Retrieved 14 September 2019.

[Hitchcock_and_Cronquist-7] Hitchcock, C.L. and Cronquist, A. 2018. Flora of the Pacific Northwest, 2nd Edition, p. 55. University of Washington Press, Seattle.

[8] "Adiantum aleuticum". Royal Horticultural Society. Retrieved 2 January 2018.

[:2-9] "RHS Plant Selector - Adiantum aleuticum 'Subpumilum'". Retrieved 23 February 2020.

[10] Hoshizaki, Barbara Joe; Moran, Robbin C. (2001). Fern Grower's Manual. Portland, Oregon: Timber Press. p. 160. ISBN 9780881924954.

[gledhill-11] Gledhill, David (2008). "The Names of Plants". Cambridge University Press. ISBN 9780521866453 (hardback), ISBN 9780521685535 (paperback). pp 36, 42

[12] "Adiantum aleuticum 'Japonicum'". BBC Gardeners' World Magazine. Retrieved 2021-03-31.

[13] "Buy five-fingered maidenhair fern ( syn. Adiantum pedatum ) Adiantum aleuticum 'Imbricatum'". www.rhsplants.co.uk. Retrieved 2021-03-31.

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