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Christmas Fern (Polystichum acrostichoides)

Life history

Species overview

Christmas Fern (Polystichum acrostichoides), a Wisconsin Special Concern plant, is found in rich, mesic woods. This species can be identified year-round.

Synonyms: Nephrodium acrostichoides, Polystichum acrostichoides var. acrostichoides, Polystichum acrostichoides var. schweinitzii


  • Distinguishing characteristics: Blade not reduced at the base; fertile pinnae smaller than the sterile.
  • Flower characteristics:
  • Fruit characteristics: Sori commonly in 2 rows on each side of the midrib; indusium thick, entire, blackish when dry.
  • Leaf characteristics: 3 to 7.5 dm, the green petiole .25 to .6 times as long as the blade; blade pinnate, 5 to 12 cm wide, lance-linear, tapering to a sharp point at the tip, not reduced at the base; 20 to 35 pairs of alternate pinnae, linear-oblong, acute, with distinct, ear-shaped appendages at the upper base, dark green and scaleless above, paler and with hair-like scales beneath; fertile upper pinnae abruptly smaller.


  • Blooming phenology:
  • Fruiting phenology: mid May through July
  • Optimum time to identify: This species can be identified year-round


  • Growth form: Fern
  • Vegetative reproduction: Rhizomatous
  • Life cycle: Perennial
  • Comments: Associated Species: Acer saccharum, Fagus grandifolia, Tilia americana, Ostrya virginiana, Cicaea alpina, Actaea rubra, Smilacina racemosa, Hepatica acutiloba, Adiantum pedatum, Botrychium virginianum.

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

The table below provides information about the protected status - state and federal - and the rank (S and G Ranks) for Christmas Fern (Polystichum acrostichoides). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where this species has been found to date and is not meant as a range map.

Documented locations of Polystichum acrostichoides in the Natural Heritage Inventory Database as of July 2015.

Summary Information
State StatusSC
Federal Status in Wisconsinnone
State RankS2
Global RankG5
Tracked by NHIY

Habitats and landscapes

The Natural Heritage Inventory has developed scores indicating the degree to which each of Wisconsin's rare plant species is associated with a particular natural community or ecological landscape. This information is similar to that found in the Wildlife Action Plan for animals. As this is a work in progress, we welcome your suggestions and feedback.

General habitat information

  • Habitat description: Found in rich, mesic woods.
  • Soils: Well-drained, circumneutral to subacid soils.

Natural communities

This table lists the natural communities that are associated with Christmas Fern. Scores for natural community associations are: "significant" association (score=3), "moderate association" (score=2) or the species can be present but is only weakly associated with the community (score=1).

Ecological landscapes

This table lists the ecological landscape association scores for Christmas Fern. The scores (3=High, 2=Moderate, 1=Low, 0=None) also correspond to the map.

Map of the Ecological Landscapes of Wisconsin.

Species guidance

The Endangered Resources Program has developed avoidance measures and management guidelines for plants on the Natural Heritage Working List. These are a work in progress, and we welcome your suggestions and feedback. Sources used in developing this information can be found here.

Avoidance measures

These are specific actions designed to avoid "take" (mortality) of this species.

  • Avoid known individual plant locations and conduct operations elsewhere when they are least likely to cause damage. Ideally, this would involve frozen, snow-covered ground. However, in areas of the state where frozen conditions are unreliable, very dry soils late in the growing season might be the best available alternative. Consult with a biologist, if needed.
  • Avoid broadcast spraying of herbicides; use care with spot spraying.

Management guidance

Management guidelines are additional considerations that may help maintain or enhance habitat for this species

  • Maintain high forest canopy cover; this species requires shaded habitat conditions.


Christmas Fern Photo.

Photo © John Kohout.

Christmas Fern Photo.

Photo by  staff, Wisconsin DNR.

Christmas Fern Photo.

Photo © Kitty Kohout.

Support for Wisconsin's rare plant information has been provided by the Division of Forestry, the Endangered Resources Fund and the Wisconsin Rare Plant Preservation Fund. To donate, visit the Natural Resources Foundation of Wisconsin [exit DNR].

Last revised: Wednesday, May 05, 2021
Southwest Savanna Southern Lake Michigan Coastal Western Coulees and Ridges Southeast Glacial Plains Central Sand Hills Central Lake Michigan Coastal Central Sand Plains Northern Lake Michigan Coastal Northern Lake Michigan Coastal Northeast Sands Western Prairie North Central Forest Northern Highlands Northwest Lowlands Northwest Sands Northwest Lowlands Superior Coastal Plains Forest Transition