Burke: Polystichum imbricans vs. Polystichum kruckebergii

	Polystichum imbricans	Polystichum kruckebergii
	imbricate sword-fern, rock sword-fern	holly fern, Kruckeberg's sword fern fern
Habit		Terrestrial perennials with ascending stems.
Leaves		Leaves monomorphic, erect, 1-2.5 dm, lacking bulblets; petiole 1/5 length of leaf or less, with sparse covering of light brown scales that become smaller distally; blade linear, 1-pinnate-pinnafitid, base narrowed; pinnae rhombic-ovate to short-falcate, proximal pinnae somewhat triangular, pinnae overlapping and twisted slightly out of blade plane, 0.5-1.5 cm, base oblique, acroscopic auricle distinct, margins shallowly cut to barely dentate or finely serrated, teeth spreading and spiny at tip, apex acute; microscales lanceolate, confined to costa on bottom surface.
Spores		Indusia entire; spores dark brown.

	Polystichum imbricans	Polystichum kruckebergii
Habitat	Drier habitats such as open rock crevices and dry conifer forest, occasionally on serpentine, mostly at low elevations.	Open slopes, typically among rocks; tolerant of serpentine.
Distribution	Occurring on both sides of the Cascades crest in Washington; southwestern British Columbia to California, eastern Idaho, and northern Idaho. [WildflowerSearch map] [BONAP county map]	Occurring in the Olympics and Cascades mountains in Washington; southeast Alaska to California, east to Montana, Idaho, Nevada and Utah. [WildflowerSearch map] [BONAP county map]
Origin	Native	Native
Conservation status	Not of concern	Not of concern
Sibling taxa	P. andersonii, P. braunii, P. californicum, P. californicum × P. munitum, P. kruckebergii, P. kruckebergii × P. munitum, P. lemmonii, P. lemmonii × P. munitum, P. lemmonii × P. scopulinum, P. lonchitis, P. munitum, P. munitum × P. scopulinum, P. scopulinum	P. andersonii, P. braunii, P. californicum, P. californicum × P. munitum, P. imbricans, P. kruckebergii × P. munitum, P. lemmonii, P. lemmonii × P. munitum, P. lemmonii × P. scopulinum, P. lonchitis, P. munitum, P. munitum × P. scopulinum, P. scopulinum
Subordinate taxa	P. imbricans ssp. imbricans
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	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

imbricate sword-fern, rock sword-fern

holly fern, Kruckeberg's sword fern fern

Habit

Terrestrial perennials with ascending stems.

Leaves

Leaves monomorphic, erect, 1-2.5 dm, lacking bulblets;

petiole 1/5 length of leaf or less, with sparse covering of light brown scales that become smaller distally;

blade linear, 1-pinnate-pinnafitid, base narrowed;

pinnae rhombic-ovate to short-falcate, proximal pinnae somewhat triangular, pinnae overlapping and twisted slightly out of blade plane, 0.5-1.5 cm, base oblique, acroscopic auricle distinct, margins shallowly cut to barely dentate or finely serrated, teeth spreading and spiny at tip, apex acute;

microscales lanceolate, confined to costa on bottom surface.

Spores

Indusia entire; spores dark brown.