Anderson's Swordfern - Polystichum andersonii
(see State Rank Reason below)
MNPS Threat Rank
State Rank Reason (see State Rank above)
Polystichum andersonii occurs where vegetation is dense, such as moist spruce-fir forests, avalanche chutes, along streams, and shrub thickets. It is documented from about 17 locations in western Montana, but known from several more locations in the Cabinet and Bitterroot Mountains. Though its habitat may be limited in Montana, populations are present and appear stable. It can grow as a sterile hybrid that develops large colonies through vegetative propagation by its bulblets.
Leaves arching, 20–70 cm long, commonly with 1 to several scaly, bulblets on central axis among upper pinnae. Leaf blade narrowly elliptic or lanceolate. Pinnae narrowly lanceolate, the lower deeply divided, 2–10 cm long with sharp-pointed lobes. Indusium with sparse marginal hairs (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
In MT known only from Lincoln, Flathead and Ravalli counties; AK south to OR and MT (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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- Additional ReferencesLegend: View Online Publication
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- Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.