Flora of North America species comparison

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Polystichum microchlamys

Polystichum scopulinum

attu hollyfern

Eaton's holly fern, mountain holly fern, polystic des rochers, rock sword fern
Stems

erect.

ascending.
Leaves

arching, 3–8 dm;

bulblets absent.

erect, 1–3(–5) dm;

bulblets absent.
Petiole

1/8–1/4 length of leaf, densely scaly;

scales brown, diminishing in size distally.

1/5–1/3 length of leaf, densely scaly but scales falling off distally;

scales light brown, abruptly diminishing in size distally.
Blade

broadly lanceolate, 1-pinnate-pinnatifid, base slightly narrowed.

narrowly lanceolate, 1-pinnate-pinnatifid, base narrowed.
Pinnae

narrowly lanceolate, not overlapping, in 1 plane, 3–13 cm;

base oblique, proximal acroscopic segments enlarged;

margins incised to costa but segments sessile and adnate to costa for at least 2 mm, segments excised and decurrent, serrulate-spiny with teeth spreading to ascending;

apex acute with subapical and apical teeth same size;

microscales filiform, dense abaxially, sparse adaxially.

oblong-lanceolate, overlapping, folded inward and twisted horizontally, 1–3 cm;

base oblique;

margins serrulate with teeth curved inward;

apex obtuse to cuspidate with subapical teeth smaller than apical tooth;

microscales narrowly lanceolate, with stout projections, sparse, on abaxial surface only.
Indusia

erose-dentate.

entire-ciliate.
Spore(s)

color unknown.

brown.
2n

= 164.

Polystichum microchlamys

Polystichum scopulinum
Habitat Terrestrial Rock crevices and at base of boulders, serpentine to acidic substrates, usually exposed to full sun
Elevation 0–100 m (0–300 ft) 0–3500 m (0–11500 ft)
Distribution
from FNA
AK; Asia in Kamtchatka and Japan
[BONAP county map]
from FNA
AZ; CA; CO; ID; MT; NV; OR; UT; WA; WY; BC; NF; QC
[WildflowerSearch map]
[BONAP county map]
Discussion

Polystichum microchlamys is found in the flora only on Attu, at the western tip of the Aleutian Archipelago.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Polystichum scopulinum is widely distributed in the United States west of the 110th meridian, where it occurs in sporadic, usually small populations. The species is abundant only on montane serpentine outcrops. The populations in Newfoundland and Quebec are dramatically disjunct.

Polystichum scopulinum is an allopolyploid, believed on morphologic grounds to be derived from P. imbricans × lemmonii (D. H. Wagner 1979). Based on putative hybridization between P. scopulinum and P. munitum (P. S. Soltis et al. 1989; W. H. Wagner Jr. 1973), however, P. munitum may also be involved. This hybrid is discussed under P. californicum.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 2. FNA vol. 2.
Parent taxa Dryopteridaceae > Polystichum Dryopteridaceae > Polystichum
Sibling taxa
P. acrostichoides, P. aleuticum, P. andersonii, P. braunii, P. californicum, P. dudleyi, P. imbricans, P. kruckebergii, P. kwakiutlii, P. lemmonii, P. lonchitis, P. munitum, P. scopulinum, P. setigerum
P. acrostichoides, P. aleuticum, P. andersonii, P. braunii, P. californicum, P. dudleyi, P. imbricans, P. kruckebergii, P. kwakiutlii, P. lemmonii, P. lonchitis, P. microchlamys, P. munitum, P. setigerum
Synonyms Aspidium microchlamys Aspidium aculeatum var. scopulinum, P. mohrioides var. scopulinum
Name authority (H. Christ) Matsumura: Index Pl. Jap. 1: 343. (1904) (D. C. Eaton) Maxon: Fern Bull. 8: 29. (1900)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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