Polystichum braunii

Braun's Holly Fern

Braun's Holly Fern, Photo courtesy Wisconsin State Herbarium and Eric J. Epstein
Braun's Holly Fern
Photo courtesy Wisconsin State Herbarium
and Eric J. Epstein

Flora, fauna, earth, and sky...
The natural history of the northwoods


Name:

  • Polystichum, from the Greek polus (polus), "many", and sticos (stichos), "row or file", a reference to the regular rows of fruitdots common to this genus of ferns.
  • braunii, after botanist Alexander Braun (1805-1877).
  • Common name from the holly-like appearance of the leaflets.
  • Other common names include Braun's Sword Fern, Eastern Holly Fern, Skuggbräken (Swe), Junkerbregne (Nor), Håret Skjoldbregne (Dan), Brauns Schildfarn, Zarter Schildfarn (Ger), Naaldvaren (NL), Polystic de Braun (Fr)

Taxonomy:

  • Kingdom Plantae, the Plants
    • Division Polypodiophyta, the True Ferns
      • Class Filicopsida
        • Order Polypodiales
          • Family Dryopteridaceae, the Wood Ferns
            • Genus Polystichum, the Holly Ferns
  • Taxonomic Serial Number: 17678
  • Also known as Aspidium braunii
  • Our North American plant has been further taxonomized as var. purshii to distinguish it from the European var. braunii. (It's a matter of relative breadth of microscales.)

Description:

  • Fronds monomorphic, arching, 12"-16"
    • Petiole (leaf stalk) 1/8-1/6 length of leaf, densely covered in light brown scales.
    • Blade broadly lanceolate and twice-cut; base narrowed. Upper surface dark green and glossy; underside scaly.
    • Rachis (axis) densely covered in light brown scales.
    • Pinnae (primary leaflets) oblong-lanceolate, lower pinnae more-or-less rectangular, not overlapping, and in a single plane, ¾"-4" long.
    • Pinnules (secondary leaflets) slightly stalked, edges toothed, with slender bristle tips.
  • Rootstalk short, stout, erect, and very scaly.
  • Sori few, small, and well-spaced.
    • Indusia ciliate.
    • Spores brown.
Frond detail; Photo courtesy Wisconsin State Herbarium and Tim Kessenich

Identification:

  • Identifiable by its dark green fronds, narrowed at both tip and base, and covered with scales on the underside.
  • Field Marks
    • large size
    • frond shape and color
    • profuse scales
    • bristle tipped pinnules
  • Collected in our area from Cook and Lake Counties but not St. Louis.

Distribution:

  • Alaska, the Yukon, and British Columbia; Northern Idaho; Ontario to Newfoundland, south to Minnesota, Wisconsin, Michigan, New York, and Massachusetts. Also Eurasia.

Habitat:

  • Cool, moist, shaded places in boreal forests and northern deciduous woods; also rocky slopes and moist cliffs.
  • Sensitive to logging activity

Fire:

Associates:

History:

Uses:

Reproduction:

  • By spore and vegetatively by rhizome

Propagation:

  • By rhizome division

Cultivation:

  • Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)
  • Cultural Requirements
    • Shade
    • Moist organic soil
  • Available by mail order from specialty suppliers.

Links:

Comments:

Valley Internet Company
Return to Home Page
Send Feedback to Webmaster

Last Updated on 26 February, 2004