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Mountain Swordfern - Polystichum scopulinum
Other Names:
Mountain Hollyfern
State Rank Reason (see State Rank above)
Only two known locations from western Montana. Very little data are available for the known occurrences. Additional surveys are needed.
- Details on Status Ranking and Review
Population Size
Score3 - Vey Small: Generally <2,000 individuals.
CommentEstimated. No population data available.
Range Extent
Score1 - Peripheral, Disjunct or Sporadic Distribution in MT: Widespread species that is peripheral, disjunct or sporadically distributed within MT such that it occurs in <5% of the state (<7,500 sq. miles or the combined area of Beaverhead and Ravalli Counties) or is restricted to 4-5 sub-basins.
Area of Occupancy
Score3 - Very Low: Generally occurring in 3 or fewer Subwatersheds (6th Code HUC’s).
Environmental Specificity
Score1-2 - Moderate to High.
Trends
Score0-3 - Population trends are unknown.
Threats
Score1-2 - Medium to High.
CommentThough no specific threats have been identified, known occurrences are near trails and a riverbank providing the opportunity for negative impacts.
Intrinsic Vulnerability
Score1-2 - Moderate to High Vulnerability.
Raw Conservation Status Score
Score
10 to 16 total points scored out of a possible 19.
General Description
Mountain Holly-fern has evergreen fronds that are 10-40 cm long, and clustered on a short, stout, scaly rhizome. The blades are made up of 20-40 primary pinnae on each side of the rachis. The primary pinnae are 1.5-3.2 cm long, and pinnately lobed with large basal lobes. Above the basal lobes, the pinnae are 1/3 to 1/2 as wide as long, and the lobes become progressively more shallow-cut and tooth-like. The lobes or teeth are inconspicuously sharp-tipped, and the apical tooth is larger than those nearest it. Circular clusters of sporangia borne on the undersides of the middle and upper
pinnae are covered by indusia.
Phenology
Producing spores in June; evergreen and identifiable in all seasons.
Diagnostic Characteristics
The species is most similar to P. kruckebergii, both distinguished from other Montana hollyferns by having pinnae with large basal lobes. The latter differs in having shorter pinnae mostly 0.5-1.5 cm long that are 1/2 to as wide as long, with lobes or teeth that end in minute tips, and the apical tooth is not much larger than those nearest it.
Species Range
Montana Range
Range Descriptions
Native
Range Comments
In MT known from Ravalli and Sanders counties; BC to MT south to CA and AZ, disjunct in QC and NL (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations: 3
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
Relative Density
Recency
(Observations spanning multiple months or years are excluded from time charts)
Habitat
Moist rock crevices in subalpine zone, and moist rocks along rivers in the valleys.
Stewardship Responsibility
Threats or Limiting Factors
STATE THREAT SCORE REASON
Threat impact not assigned because threats are not known (MTNHP Threat Assessment 2021).
References
- Literature Cited AboveLegend:
View Online Publication- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
MTNHP Threat Assessment. 2021. State Threat Score Assignment and Assessment of Reported Threats from 2006 to 2021 for State-listed Vascular Plants. Botany Program, Montana Natural Heritage Program, Helena, Montana.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?- Lackschewitz, K. H. 1976. Montana mountain flora: new records. Madrono 23:360-362.
- Lackschewitz, K., P. Lesica, and J. S. Shelly. 1988. Noteworthy collections: Montana. Madrono 35:355-358.
- Lellinger, D.B. 1985. A Field Manual of the Ferns and Fern-Allies of the United States and Canada. Smithsonian Inst. Press. Washington, D.C. B85LEL01PAUS
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p.
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