Mountain Holly Fern
Scientific Name: Polystichum scopulinum
Taxonomy Group: Vascular Plants
Range: British Columbia, Quebec, Newfoundland and Labrador
Last COSEWIC Assessment: May 2005
Last COSEWIC Designation: Threatened
SARA Status: Schedule 1, Threatened
Image of Mountain Holly Fern
Mountain Holly Fern is a perennial fern growing in compact tufts. Its underground stem, or rhizome, is short and stout. The erect evergreen fronds (leaves made up of leaflets) are 10 to 50 cm long and 3 to 7 cm wide and pinnate, meaning they grow in leaflets on each side of the midrib, like the quills of a feather. On each side of the midrib, or rachis, are 20 to 40 oblong leaflets divided into tiny acute segments, which in turn are minutely spiny-toothed. Round structures, called sori, are attached near the rachis and are protected by a membrane. Sori are clusters of sacs containing the spores, the reproductive cells that will germinate and grow into new plants.
Distribution and Population
The range of Mountain Holly Fern extends from southwestern British Columbia sporadically south in the western United States to Colorado, Arizona, and California. Disjunct populations have also been recorded in northeastern Quebec and the western part of the island of Newfoundland. There are five known Mountain Holly Fern populations in Canada. The three recorded populations in British Columbia all occur in the Tulameen River area, northwest of Princeton in southwestern British Columbia. The only known population in Quebec is on Mont Albert in the Gaspé Peninsula. The population on the island of Newfoundland was recorded in 1950 from the Humber West area (North Arm Mountain) in the western part of the island. The current status of this historical population is still unknown despite recent limited searches. The three British Columbia populations contain a total of between 5 and 400 plants. It is quite likely that a number of other Mountain Holly Ferns occur in the same area, but the rugged terrain makes access extremely difficult. The total population of Mountain Holly Fern in British Columbia was stable between 1996 and 2002. The single Quebec population consists of nine small colonies in close proximity, with a total of about 215 plants. Because of the rugged terrain, it is possible that other individuals could be found in the Vallée du Diable or on the southern slope of Mont Albert. The population is thought to be stable. No specific information is available for the Newfoundland population, which was last seen in 1950. The population may still be extant, but, if so, it is likely highly restricted in size.
In North America, Mountain Holly Fern grows in a specialized habitat consisting of shallow soil with a high concentration of heavy metals over a substrate of rocks containing iron and magnesium silicate (ultramafic rocks), mainly olivine and serpentine. These rocks provide dry, alkaline soil habitats characterized by very sparse vegetation cover and the absence of trees. Although a number of such rock outcrops occur in western British Columbia, Mountain Holly Fern is restricted to a band between Olivine Mountain and Grasshopper Mountain in the Tulameen River valley. These slopes have a typically limited flora, in contrast with the dense surrounding montane forests dominated by Douglas-fir. In Quebec, Mountain Holly Fern is restricted to the south-facing slopes of the Vallée du Diable (the eastern side of Mont Albert), where the flora is similarly limited. The population observed in Newfoundland occurred on the southerly slopes of a serpentine ridge.
Only limited information is available on the biology of Mountain Holly Fern. Plants adapted to the habitat preferred by this species can tolerate low levels of calcium, nitrogen, phosphorus, and molybdenum and high levels of magnesium, chromium, and nickel. These rock outcrop habitats are also characterized by shallow soils and sparse vegetative cover—an extremely dry microclimate that excludes many species growing nearby. Like most evergreen fern species, Mountain Holly Fern often retains significant numbers of mature spores over the winter, to be released the following spring. Because of the dry site conditions, which are not ideal for spore germination or gamete fertilization, most reproduction is probably vegetative, by rhizome elongation, often resulting in large clumps of clones.
The primary threat to Mountain Holly Fern at this time is mining exploration. All ultramafic outcrops in British Columbia have potential for the presence of precious metals, and all such geologic formations have established mineral claims. Road construction and forest fires are also major threats to the British Columbia populations. The largest population, on Britton Creek, is especially threatened by road upgrading, since the site would either have a new cut established or serve as a borrow pit. Forest fires pose a significant threat in the Tulameen River valley, where there are high fuel loads on the forest floor. In Quebec, botanical over-collecting is thought to have significantly reduced the population in the first half of the 20th century; however, no such threat exists at this time. Since some of the colonies are on a trail, trampling may be a potential threat. Threats, if any, cannot be determined at present for the historical Newfoundland population, which was in a relatively inaccessible location.
Federal ProtectionThe Mountain Holly 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
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for the Mountain Holly Fern (Polystichum scopulinum) in Canada
Status First posting on SAR registry
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.
9 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- COSEWIC Assessments (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Orders (2 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
- Recovery Document Posting Plans (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
COSEWIC Annual Report - 2005 (2005)2005 Annual Report to the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.
Recovery Document Posting Plans
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