Taxon Report

Polystichum kruckebergii W. Wagner

Kruckeberg's sword fern

Print Report

Taxon Summary

Polystichum kruckebergii, commonly known as Kruckeberg's sword fern, is a perennial rhizomatous herb in the Dryopteridaceae that is found in California and elsewhere. It occurs within Subalpine coniferous forest, and Upper montane coniferous forest, growing at elevations from 2100 to 3200 meters. Polystichum kruckebergii is ranked 4.3, Plants of Limited Distribution, A Watch List; Not very threatened in California.

Classification


Scientific Name:	Polystichum kruckebergii W. Wagner
Common Name:	Kruckeberg's sword fern
Family:	Dryopteridaceae
Element Code:	PPDRY0R0C0
USDA Plants Symbol:	POKR
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial rhizomatous herb
Blooming Period: Jun-Aug	Jun-Aug
Elevation:	2100-3200 (6890-10500)
General Habitats:	Subalpine coniferous forest, Upper montane coniferous forest
Microhabitat:	Rocky
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	4.3
Global Rank:	G4
State Rank:	S4
State List:	None
Fed List:	None
Other Status:
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	0
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	0
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	0

Location


California Endemic: False
California Counties and Islands: Name (Code)
San Bernardino (SBD)?, Siskiyou (SIS), Tuolumne (TUO)
Quads: Name (Quad Code)
Boulder Peak (4112351), Dunderberg Peak (3811913), Marble Mountain (4112352), Medicine Lake (4112155)

Threat List Data from the CNDDB


Threat List Total:	0
EOs with Threat Listed:	Total EOs	% of EOs
	0	0 %

Notes



SBD Co. records need verification; Parish specimens are likely P. scopulinum. Sensitive in ID, and on watch list in OR. See American Fern Journal 56:4 (1966) for original description, and Pteridologia 1:1-64 (1979) for taxonomic treatment.
Threats:

Taxonomy:

Selected References

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 29 October 2025].