OregonFlora: Polystichum munitum

	Polystichum munitum
	common sword fern, western sword fern
Stems	typically short and erect.
Leaves	robust; to 150 cm; in dense crowns; bulbils absent.
Petioles	up to 25% leaf length, densely chaffy near base, becoming sparser distally; chaffy scales present along the length of the rachis and costae.
Blades	1-pinnate, narrowly lanceolate, tapered to the apex, not or scarcely reduced towards base; microscales lanceolate or narrowly ovate; long-acuminate.
Pinnae	linear-lanceolate; to approximately 9.5 × 1 cm (above the anterior lobe), often falcate, not overlapping; in 1 plane to twisted; margins serrulate with small, regular spine-tipped teeth; the spines bent forward and parallel to the margin, acroscopic auricle large, broadly triangular to ovate, with a prominently cuspidate apex and lateral teeth similar to those on the pinna margin.
Sori	with fimbriate/ciliate indusial margins.
2n	=82.

	Polystichum munitum
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Understories of moist forests, meadows, rocky sites. 0–2200 m. BW, Casc, CR, ECas, Est, Sisk, WV. CA, ID, WA; north to AK, east to SD. Native. This species is so abundant in the Pacific Northwest that one might forget to look for other pinnate sword ferns. At higher elevations, P. lonchitis is identified by narrowing blade bases and spreading spines on the pinna margins versus scarcely reduced blade bases and incurved spines in P. munitum. On moist, sunny, rocky sites the pinnae of P. munitum may be twisted like venetian blinds, making it look much like P. imbricans ssp. imbricans. Besides the characters listed in the key, these species also differ in the distribution of chaffy scales. In P. imbricans ssp. imbricans, these are concentrated on the proximal portion of the petiole, while in P. munitum they occur all along the length of the petiole and rachis. Polystichum munitum is widely cultivated as an ornamental, and leaves are harvested from Oregon forests for sale to florists.
Source	Flora of Oregon, volume 1, page 76 Duncan Thomas
Sibling taxa	P. andersonii, P. andersonii x Polystichum munitum, P. californicum, P. californicum x Polystichum munitum, P. imbricans, P. kruckebergii, P. lemmonii, P. lonchitis, P. scopulinum
Synonyms	Polystichum munitum var. munitum
Web links	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

Polystichum munitum

common sword fern, western sword fern

Stems

typically short and erect.

Leaves

robust; to 150 cm; in dense crowns; bulbils absent.

Petioles

up to 25% leaf length, densely chaffy near base, becoming sparser distally; chaffy scales present along the length of the rachis and costae.

Blades

1-pinnate, narrowly lanceolate, tapered to the apex, not or scarcely reduced towards base;

microscales lanceolate or narrowly ovate; long-acuminate.

Pinnae

linear-lanceolate; to approximately 9.5 × 1 cm (above the anterior lobe), often falcate, not overlapping; in 1 plane to twisted;

margins serrulate with small, regular spine-tipped teeth; the spines bent forward and parallel to the margin, acroscopic auricle large, broadly triangular to ovate, with a prominently cuspidate apex and lateral teeth similar to those on the pinna margin.

Sori

with fimbriate/ciliate indusial margins.

=82.

Polystichum munitum

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Understories of moist forests, meadows, rocky sites. 0–2200 m. BW, Casc, CR, ECas, Est, Sisk, WV. CA, ID, WA; north to AK, east to SD. Native.

This species is so abundant in the Pacific Northwest that one might forget to look for other pinnate sword ferns. At higher elevations, P. lonchitis is identified by narrowing blade bases and spreading spines on the pinna margins versus scarcely reduced blade bases and incurved spines in P. munitum. On moist, sunny, rocky sites the pinnae of P. munitum may be twisted like venetian blinds, making it look much like P. imbricans ssp. imbricans. Besides the characters listed in the key, these species also differ in the distribution of chaffy scales. In P. imbricans ssp. imbricans, these are concentrated on the proximal portion of the petiole, while in P. munitum they occur all along the length of the petiole and rachis. Polystichum munitum is widely cultivated as an ornamental, and leaves are harvested from Oregon forests for sale to florists.