OregonFlora: Polystichum kruckebergii

	Polystichum kruckebergii
	Kruckeberg's holly fern, Kruckeberg's sword fern
Stems	ascending.
Leaves	small, mostly under 20 cm; bulbils absent.
Petiole	variable in length from very short up to almost 50% of the leaf length; chaffy at base; scales sparser distally and present on at least the proximal part of the rachis.
Blades	1-pinnate-pinnatifid (sometimes 1-pinnate), narrowly lanceolate, not much reduced basally; microscales narrow, confined to the abaxial costa.
Pinnae	more or less ovate; small; to about 1.5 cm, overlapping, usually twisted out of plane; distal part strongly spiny-dentate with spreading spines; a few proximal segments more deeply incised, with several spreading spines, acroscopic lobe enlarged, sometimes forming a distinct pinnule.
Sori	with entire indusium.
2n	=164.

	Polystichum kruckebergii
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Rocky places. 800–3000 m. BR, BW, ECas. CA, ID, NV, WA; most of western North America. Native. Polystichum kruckebergii can appear pinnate, with even the proximal pinna segments not deeply lobed. It then resembles P. lonchitis, from which it differs in its more rounded pinnae with broader teeth. It can also be hard to distinguish from small specimens of P. scopulinum. The spores of P. kruckebergii are darker in color than the brown or yellow/brown spores of P. scopulinum. According to Wagner (1979), both species are allopolyploids that share one common parent (P. lemmonii × P. lonchitis = P. kruckebergii; P. lemmonii × P. munitum = P. scopulorum).
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. lemmonii, P. lonchitis, P. munitum, P. scopulinum
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 kruckebergii

Kruckeberg's holly fern, Kruckeberg's sword fern

Stems

ascending.

Leaves

small, mostly under 20 cm; bulbils absent.

Petiole

variable in length from very short up to almost 50% of the leaf length; chaffy at base;

scales sparser distally and present on at least the proximal part of the rachis.

Blades

1-pinnate-pinnatifid (sometimes 1-pinnate), narrowly lanceolate, not much reduced basally;

microscales narrow, confined to the abaxial costa.

Pinnae

more or less ovate; small; to about 1.5 cm, overlapping, usually twisted out of plane;

distal part strongly spiny-dentate with spreading spines; a few proximal segments more deeply incised, with several spreading spines, acroscopic lobe enlarged, sometimes forming a distinct pinnule.

Sori

with entire indusium.

=164.

Polystichum kruckebergii

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Rocky places. 800–3000 m. BR, BW, ECas. CA, ID, NV, WA; most of western North America. Native.

Polystichum kruckebergii can appear pinnate, with even the proximal pinna segments not deeply lobed. It then resembles P. lonchitis, from which it differs in its more rounded pinnae with broader teeth. It can also be hard to distinguish from small specimens of P. scopulinum. The spores of P. kruckebergii are darker in color than the brown or yellow/brown spores of P. scopulinum. According to Wagner (1979), both species are allopolyploids that share one common parent (P. lemmonii × P. lonchitis = P. kruckebergii; P. lemmonii × P. munitum = P. scopulorum).