Cryptogramma stelleri

Slender Cliff Brake

Slender Cliff Brake
Photo courtesy Wisconsin State Herbarium
and Tim Kessenich

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

Name:

• Cryptogramma, from the Greek, kruptos (cryptos), "hidden", and gramma (gramma), "line"; the hidden line being the row of fruitdots hidden by the overlapping leaflets.
• stelleri, after 18th Century naturalist George Steller, who accompanied the Bering expedition of 1741 and lent his name to several northwestern species, including Steller's Jay and Steller's Sea Lion.
• Common name from its delicate form and preferred habitat
• Other common names include Slender Rock Brake, Fragile Rock Brake, Steller's Rock Brake, cryptogramme de steller (Qué)

Taxonomy:

• Kingdom Plantae, the Plants
• Division Polypodiophyta, the True Ferns
  • Class Filicopsida
    • Order Polypodiales
      • Family Pteridaceae
        • Genus Cryptogramma, the Rock Brakes
• Taxonomic Serial Number: 17462
• Also known as Pteris stelleri

Description:

• A tiny, fragile, and rarely seen fern.
• Fronds scattered along stems, ephemeral (dying by late summer), soon shed
  • Sterile Fronds ovate, low arching, and fragile; 1"-6"
    • Pinnae (primary leaflets) ovate, with broadly rounded form and crinkled edges. Not particularly fern-like.
    • Pinnules (secondary leaflets) fan-shaped and shallowly lobed, with short stems and toothed edges; delicate and almost translucent; often crowded together and overlapping.
  • Fertile Fronds erect, lanceolate, and spreading; 2"-8"
    • Petiole longer than blade, dark brown below becoming greenish above, smooth and only slightly furrowed.
    • Blade broadly lanceolate to ovate-lanceolate, twice-cut, herbaceous to membranous, thin.
    • Pinnae horizontal to ascending, lanceolate to linear, 8-25mm × 2-4mm;
    • Pinnules narrow, lance-shaped, and pointed, with distinct stems; edges curled under, forming continuous false indusia and often covering entire underside of subleaflet
  • Rootstalk creeping with limited branching; slender (1mm-1.5mm in diameter), succulent, and brittle; scales pale brown.
  • Roots few, fine, shallow, and spreading

Identification:

• Unmistakeable during its short season
• Field Marks
  • small size
  • distinctively different fertile and sterile fronds

Distribution:

• Central Alaska, south through the Yukon and British Columbia to NE Washington and NW Montana; in the east, from Ontario to Newfoundland, south to Minnesota, Iowa, Illinois, Michigan, New York, Pennsylvania, and New Jersey. Isolated populations in Wyoming and Colorado mountains.
• Also the Russian Far East, China, Japan, and Taiwan.
• Kown only from Lake County in our area, but may simply be overlooked.

Habitat:

• Cool, moist, sheltered calcareous cliff crevices and rock ledges, typically in coniferous forest or other boreal habitats.

Fire:

Associates:

History:

Uses:

Reproduction:

• By spore and vegetatively by rhizome

Propagation:

• By spore; difficult

Cultivation:

• Hardy to USDA Zone 2 (average minimum annual temperature -50ºF)
• Not generally cultivated

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