Gymnocarpium jessoense : Nahanni Oak Fern

Scientific Name:

Kingdom: Plantae

Division:

• Tracheophyta (vascular)
• Pteridophyta (spore bearing)

Class: Polypodopsida (fern class)

Family: Aspidiaceae (Fern Family)

Genera: Gymnocarpium (Oak Ferns)

Species: jessoense

Synonym(s): G. robertianum, Dryopteris robertianum

English Name(s):

Nahanni Oak Fern,

First Nation Names:

Structure:

• Arising from a slender blackish rhizome (roots stalk).
• Fronds Ternate. Two side divisions smaller than the middle one.
• Fronds up to 30cm long.

Leaves:

• Blades glandular (with glands).
• Lowest leaflet on side divisions smaller than the leaflet three rows up the middle division. See diagram.

Reproductive Parts:

• Indusium (sori cover) absent.
• Sori (spore clusters) small, round, situated near leaf margin.

Seed:

• Reproduces by spores.

Not to Be Confused With:

• C.montana is another ternate fronded fern in our area. It can be distinguished by its hood-shaped inducium over its generally larger sori.
• G.dryopteris is another ternate fronded fern in our area.
• Compare the G.Jessoense diagram with the G.dryopteris diagram.

Physiology:

• In certain areas transitions between G.dryopteris and G.jessoense have been described.

Life Cycle:

• perennial from rhizome (root stalk).

Seasonal Cycle:

• Fronds deciduous (dieing back).

Animal Uses:

Habitat:

• Calcarious (basic) rock cliffs, and moist rocky woods.

Modern:

Industrial:

Medicinal:

Food:

Traditional Gwich'in:

Folklore:

Industrial:

Medicinal:

Food:

Traditional Other:

Folklore:

Industrial:

Medicinal:

Food: