Polystichum imbricans |
Polystichum andersonii |
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imbricate sword-fern, narrow-leaf sword fern, rock sword-fern |
Anderson's holly-fern, Anderson's sword fern, Vancouver holly fern |
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Stems | ascending to erect. |
erect. |
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Leaves | erect to arching back at tip, 2–8 dm; bulblets absent. |
monomorphic, arching, 3–10 dm; bulblets 1 or more, on distal 1/3 of rachis. |
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Petiole | 1/4–1/3 length of leaf; scales abruptly diminishing in size distally and falling off early but retaining conspicuous tuft of brown scales at base. |
1/8–1/4 length of leaf, densely scaly; scales light brown, diminishing in size distally. |
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Blade | linear-lanceolate to linear, 1-pinnate, base not or slightly narrowed. |
lanceolate, 1-pinnate-pinnatifid; base narrowed. |
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Pinnae | oblong, slenderly lanceolate, or falcate, usually overlapping, in 1 plane or twisted out of plane of blade, 2–4 cm; base oblique, auricles well developed; margins serrulate-spiny with teeth ascending; apex cuspidate or apiculate with subapical teeth smaller than apical tooth; microscales lanceolate to linear with straight or sharply angular projections, sparse, on abaxial surface only. |
lanceolate-falcate, proximal pinnae ± triangular, not overlapping, in 1 plane, 2–10 cm; base oblique, acroscopic auricle well developed; margins incised to costae, segments adnate to costa for at least 2 mm, serrulate-spiny with teeth ascending; apex acute with subapical and apical teeth same size; microscales filiform, with contorted projections, dense abaxially, sparse adaxially. |
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Indusia | entire to sharply dentate. |
sparsely ciliate. |
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Spores | dark brown. |
light brown to brown. |
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2n | = 164. |
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Polystichum imbricans |
Polystichum andersonii |
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Habitat | Lowland coastal to midmontane forests, interior moist forests | |||||
Elevation | 100–1700 m (300–5600 ft) | |||||
Distribution |
CA; OR; WA; BC; only in the flora
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AK; ID; MT; OR; WA; BC
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Discussion | Polystichum imbricans is one of the postulated ancestors of two allopolyploids, P. californicum and P. scopulinum (D. H. Wagner 1979). Relationships to P. munitum are discussed under that species. Subspecies 2. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Polystichum andersonii is an allotetraploid (D. H. Wagner 1979); its diploid parents are P. munitum and P. kwakiutlii. The triploid cross, P. munitum × andersonii, has been analyzed cytologically (W. H. Wagner Jr. 1973). It is the only sterile hybrid in the genus that develops large colonies through vegetative propagation by its bulblets. Hybrids look very much like some of the more deeply incised forms of Polystichum munitum except that they have abundant filiform scales, abortive sori, and nearly triangular lowermost pinnae with ± equally incised acroscopic and basiscopic auricles. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 2. | FNA vol. 2. | ||||
Parent taxa | Dryopteridaceae > Polystichum | Dryopteridaceae > Polystichum | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Aspidium munitum var. imbricans, P. munitum subsp. imbricans, P. munitum var. imbricans | P. braunii subsp. andersonii, P. braunii var. andersonii | ||||
Name authority | (D. C. Eaton) D. H. Wagner: Pteridologia 1: 50. (1979) | M. Hopkins: Amer. Fern J. 3: 116, plate 9. (1913) | ||||
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