Pellaea glabella

Smooth Cliff Brake

Smooth Cliff Brake
Photo courtesy Wisconsin State Herbarium
and Kitty Kohout

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

Name:

• Pellaea, from the Greek, pellos (pellos), "dark-coloured, dusky"; a reference to the dark stem
• glabella, from the Latin, "hairless, smooth"
• Common name from from its texture and preferred habitat.
• Other common names include Dwarf Cliffbrake, Pelléade glabre (Qué)

Taxonomy:

• Kingdom Plantae, the Plants
• Division Polypodiophyta, the True Ferns
  • Class Filicopsida
    • Order Polypodiales
      • Family Pteridaceae
        • Genus Pellaea, the Cliff Brakes
• Taxonomic Serial Number: 17646
• Also known as Pellaea atropurpurea var. bushii

Description:

• An atypical fern of cliffsides, quite rare in the North Country but rather common in southeastern Minnesota.
• Fronds blue-green, monomorphic, and evergreen; 20"-58", growing clustered on stem.
  • Petiole (leaf stalk) brown, lustrous, with rounded upper surface; occasionally shows prominent articulation lines near base.
  • Blade linear-oblong to ovate-lanceolate, ½"-3" wide, once to twice cut.
  • Rachis (axis) straight, brown, and nearly smooth with a rounded upper surface.
  • Pinnae (primary leaflets) somewhat ascending, usually with 3-7 lobes. Lobes oblong-lanceolate, ¼"-¾", leathery to herbaceous, smooth except for occasional hairlike scales on underside near midrib; leaflet edges on fertile segments curled under.
• Rootstalk compact, ascending, stout, ¼"-½" in diameter; scales reddish brown.
  • Roots dark brown to black, thin, fibrous, and profuse.
• Sori pale brown, lacking indusium.

Identification:

• Unlike any other fern found in Northern Minnesota. (And perhaps best identified with the aid of good binoculars or serious climbing gear.)
• Field Marks
  • un-fernlike foliage
  • blue-green color
  • habitat on rock ledges and cliffs

Distribution:

• Ontario to Vermont, south to Texas, Arkansas, Tennessee, and Virginia.
• Collected only from St. Louis County in our area.

Habitat:

• Calcareous cliffs and ledges, usually on limestone substrates

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)
• Generally not available commercially

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