Polystichum lemmonii
Polystichum setigerum
Lemmon's holly fern, Lemmon's sword fern, Shasta fern, Shasta sword fern
Alaska holly fern, Alaska sword fern
decumbent to ascending.
erect.
erect, 1–3.5 dm;
bulblets absent.
arching, 4–10 dm;
bulblets absent.
1/5–1/4 length of leaf, sparsely scaly;
scales pale tan, abruptly diminishing in size distally.
1/8–1/5 length of leaf, densely scaly;
scales light brown, gradually diminishing in size distally.
narrowly lanceolate, 2-pinnate, scarcely narrowed at base.
lanceolate, deeply 1-pinnate-pinnatifid to 2-pinnate, base narrowed.
ovate, overlapping, folded inward and twisted horizontally, 0.5–2 cm;
base truncate to oblique, proximal acroscopic pinnules not enlarged;
apex broadly acute;
microscales narrowly lanceolate, with few projections, sparse, ± confined to costa of both surfaces.
lanceolate, not overlapping, in 1 plane, 4–8 cm, base oblique, margins incised to costa on middle pinnae, serrulate-spiny with teeth spreading-ascending, apex acute-apiculate with subapical and apical teeth same size;
microscales filiform, sparse abaxially, confined to costa adaxially.
entire or minutely dentate-erose.
erose-ciliate.
dark brown to blackish.
brown.
± stalked, rounded, acroscopic auricle not well developed, margins entire to weakly dentate, apex rounded.
= 82.
= 246.
Polystichum lemmonii
Polystichum setigerum
Polystichum lemmonii forms sterile hybrids with P. scopulinum and P. munitum. The first hybrid may be abundant where the two parents grow together, which they frequently do in the Wenatchee Mountains of Washington and Siskiyou Mountains of northern California and southwest Oregon. The hybrid is very similar to P. lemmonii but has malformed sporangia and slightly less divided pinnae than P. lemmonii. The P. lemmonii × P. munitum hybrid is morphologically indistinguishable from P. scopulinum; it is a sterile diploid reported only twice from the Wenatchee Mountains of Washington (W. H. Wagner Jr. 1973; P. S. Soltis et al. 1989). It is possible that this hybrid involves P. imbricans and not P. munitum; neither study distinguished between them.
American authors have misapplied the name Polystichum mohrioides (Bory) C. Presl, a South American species, to P. lemmonii.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Polystichum setigerum is disjunct on Attu Island at the western tip of the Aleutian Archipelago. It is presumed to be of hybrid origin, the result of a cross between P. munitum and P. braunii (D. H. Wagner 1979). This hybrid has been produced experimentally (A. Sleep and T. Reichstein 1967) and is reported from British Columbia (see discussion under P. braunii).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
