''Adiantum aleuticum'', the western maidenhair fern or Aleutian maidenhair, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

fern The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...

in the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

'' Adiantum''.

Description

''A. aleuticum'' typically grows about 18-30 inches tall and wide. The

frond A frond is 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. Other botanists allow the term frond to also apply to the lar ...

s grow tall, and are fan-shaped, light to medium green with dark brown to black stems. 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). H20150408-0024—Adiantum aleuticum—RPBG (17192418876).jpg, Tilden Regional Park California Adiantum aleuticum subsp. calderi - Flickr - brewbooks.jpg, growing on serpentine rock Adiantum aleuticum JHT iNat199860221.jpg,

Taxonomy

Formerly classified as ''A. pedatum'' var. ''aleuticum'', it was shown to be a separate species in 1991. 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. 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 Serpentinite is a metamorphic rock composed predominantly of serpentine group minerals formed by serpentinization of mafic or ultramafic rocks. The ancient origin of the name is uncertain; it may be from the similarity of its texture or color ...

rock well, and is confined to this mineral-rich rock in some areas. When growing on sunny serpentine talus and bedrock, the fronds are held vertically, giving the fern a rather different general appearance.Hitchcock, C.L. and Cronquist, A. 2018. Flora of the Pacific Northwest, 2nd Edition, p. 55. University of Washington Press, Seattle.

Cultivation

The species and its

cultivar A cultivar is a kind of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and which retains those traits when Plant propagation, propagated. Methods used to propagate cultivars include division, root a ...

'Subpumilum' have gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. It includes the full range of cultivated p ...

. Though hardy they may also be grown as

houseplant A houseplant, also known as a pot plant, potted plant, or indoor plant, is an ornamental plant cultivated indoors. for aesthetic or practical purposes. These plants are commonly found in House, homes, Office, offices, and various indoor spaces, w ...

s. They prefer low to medium light, and will grow in moist potting mix. They may prove difficult to keep alive in dry climates.

Etymology

''Adiantum'' is derived from

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

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.Gledhill, David (2008). "The Names of Plants". Cambridge University Press. (hardback), (paperback). pp 36, 42 In the US, they are suitable for USDA hardiness zones 3–8. ''Aleuticum'' means 'from the

Aleutian Islands The Aleutian Islands ( ; ; , "land of the Aleuts"; possibly from the Chukchi language, Chukchi ''aliat'', or "island")—also called the Aleut Islands, Aleutic Islands, or, before Alaska Purchase, 1867, the Catherine Archipelago—are a chain ...

Cultivars

Cultivars include: * 'Japonicum' * 'Imbricatum' * 'Subpumilum'

References

External links

PFAF: ''Adiantum aleuticum''
{{Taxonbar, from=Q4682650 aleuticum Flora of the Northwestern United States Flora of the Southwestern United States Flora of the West Coast of the United States Flora of Alberta Flora of Alaska Flora of British Columbia Flora of Maine Flora of Michigan Flora of Newfoundland Flora of Quebec Flora of Vermont Plants described in 1845