Species Profile

Southern Maidenhair Fern

Scientific Name: Adiantum capillus-veneris
Taxonomy Group: Vascular Plants
Range: British Columbia
Last COSEWIC Assessment: May 2011
Last COSEWIC Designation: Endangered
SARA Status: Schedule 1, Endangered

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Quick Links: | Photo | Description | Distribution and Population | Habitat | Biology | Threats | Protection | Recovery Initiatives | Recovery Team | National Recovery Program | Documents

Image of Southern Maidenhair Fern

Southern Maidenhair Fern Photo 1



The Southern Maidenhair Fern is a pale green, delicate fern. Its fronds are drooping and short, measuring 15 to 30 cm; they wilt at the first frost.


Distribution and Population

In Canada, the Southern Maidenhair Fern is found in only two locations, in the vicinity of the Fairmont Hot Springs in southeastern British Columbia. This is a tropical/subtropical species whose North American distribution is mainly in the southern United States (from central California to Virginia and south to Florida and Mexico). There is one other small North American population restricted to a hot springs, in South Dakota. The fern also occurs in South America and Eurasia. The Southern Maidenhair Fern has been known to occur at the Fairmont Hot Springs since 1888. It was still abundant at several sites on the resort in the 1940s, but resort development has caused the elimination of all but two sites. In 1996, only 16 sterile fronds remained on about four plants at one location, and hundreds of fronds were found at the second location in 2000. The reproductive status of the fronds at the second site has yet to be determined. The site's status is therefore extremely precarious.



The Southern Maidenhair Fern grows on lime-rich, porous rock, often on rocky cliffs and walls. At the Fairmont Hot Springs in Canada, where the plant is living more than 1000 km north of its main range, the fern requires the warm and very humid climate found in the natural hot springs environment to survive.



In Canada, the Southern Maidenhair Fern reproduces only through the expansion of the rhizome, since all the fronds die in the winter. The Canadian plants are not producing spores.



Loss of habitat, through the construction of holiday resorts and the human use of hot springs, has decimated the Canadian populations of Southern Maidenhair Ferns. Any change to the hot spring habitat at the site of the remaining population of the Southern Maidenhair Fern would destroy this population.



Federal Protection

The Southern Maidenhair Fern is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.

Provincial and Territorial Protection

To know if this species is protected by provincial or territorial laws, consult the provinces' and territories' websites.


Recovery Initiatives

Status of Recovery Planning

Recovery Strategies :

Name Recovery Strategy for the Southern Maidenhair Fern (Adiantum capillus-veneris) in Canada
Status Final posting on SAR registry


Recovery Team

Southern Maidenhair Fern Recovery Team

  • Ted Antifeau - Chair/Contact - Government of BC
    Phone: 250-354-6163  Fax: 250-354-6332  Send Email


Recovery Progress and Activities

Summary of Progress to Date A recovery team has been initiated for Southern Maidenhair Fern. Summary of Research/Monitoring Activities In surveys of Southern Maidenhair Fern, fronds are counted, so these are not all genetically unique individuals. In 1996 only four Southern Maidenhair Ferns at one site were known to remain in British Columbia. The recovery team determined that conducting surveys to locate the entire population was an urgent priority. Surveys conducted in 2000 and 2002 located three additional sites with a total of 33,650 ferns, improving the prospect for recovery. Since this time, all sites have been monitored annually. By 2004, the fern had become extirpated at one site and was almost extirpated at another site, due to drying conditions resulting from unexplained alterations in thermal spring flows. However, with over 30,000 ferns remaining at two sites, recovery remains entirely feasible. Summary of Recovery Activities The recovery team is currently preparing a management strategy for the Fairmont Resort property, where the two remaining Southern Maidenhair Ferns sites are found. In the meantime, the resort has undertaken several voluntary stewardship activities to provide habitat and protection for the fern.


PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.

5 record(s) found.

COSEWIC Status Reports

  • COSEWIC Assessment and Status Report on the Southern Maidenhair Fern Adiantum capillus-veneris in Canada (2011)

    Southern Maidenhair Fern (Adiantum capillus-veneris) is a delicate fern spreading by a thin branched rhizome covered with slender, small, brown scales. Leaves arise scattered along the rhizome and are lax or drooping. The central axis of the blade is continuous with the purplish-black leaf stalk. Blades are commonly twice compound, with each leaf consisting of a series of 5-12 alternate pinnae per side of the leaf, each pinna has a central axis and bears up to about 6 pinnules. Each of these smallest leaf segments (pinnules) is broadly rounded at the end and incised into rounded teeth; the base tapers to a small delicate leaflet stalk. These pinnules are reminiscent of miniature ginkgo leaves. The spore sacs (in fertile leaves) are clustered on the lower pinnule surface within crescent-shaped protective flaps of tissue (indusia).

COSEWIC Assessments

  • COSEWIC Assessment - Southern Maidenhair Fern (2000)

    Designated Endangered in April 1984. Status re-examined and confirmed in April 1998 and in May 2000. May 2000 assessment based on new quantitative criteria applied to information from the existing 1998 status report.

Response Statements

  • Response Statement - Southern Maidenhair Fern (2011)

    This delicate fern is known in Canada from three to four subpopulations in a single natural hot spring in southeastern British Columbia. It is threatened by changes in hydrology, development, recreational activities and collection, and is limited by availability of suitable microhabitat conditions. Large declines (greater than 90%) have been recorded in the past 10 years, though the plant may remain dormant underground and one subpopulation has rebounded after four survey years in which few or no fronds were detected.

Recovery Strategies

  • Recovery Strategy for the Southern Maidenhair Fern (Adiantum capillus-veneris) in Canada (2013)

    The federal Minister of the Environment is the competent minister for the recovery of the Southern Maidenhair Fern and has prepared this recovery strategy as per section 37 of SARA. SARA section 44 allows the Minister to adopt all or part of an existing plan for the species if it meets the requirements under SARA for content (sub-sections 41(1) or (2)). Environment Canada has adopted the British Columbia recovery strategy and prepared a federal addition to meet the requirements of SARA.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2010 - 2011 (2011)

    Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. COSEWIC held two Wildlife Species Assessment Meetings during the past year assessing the status or reviewing the classification of a total of 92 wildlife species.