Scientific Name: Blechnum cartilagineum

Common Name: gristle fern

Family Classification (Clade): Pteridophytes

Family: Blechnaceae

Threatened Species Status: Vulnerable

Permit: It is an offence to collect, disturb, damage or destroy this species unless under permit.

Form Description: Fern with pale green fronds crowded, erect broad, leathery, young fronds may be pink.

Height (m): 0.5 – 1.5

Municipality
Break O’DayCentral CoastCircular HeadDorsetKingboroughLauncestonWest Tamar
Plant Communities
Dry Eucalypt ForestRainforestWet Eucalypt Forest
Habitat Notes

Extremely rare in Tasmania. Favours sheltered sites along creeklines in northern and eastern Tasmania. Hardy enough to withstand clay soils and dry areas under established eucalypts. Tolerant of a range of soil types and positions.

Site Tolerance

Dry, Moist, Shady

Soil Tolerance

Clay, Fertile, Loam, Sandy, Well-drained

General Notes

Very hardy; clump forming; suitable for growing in large container.

Propagation Calendar

  • Flowering Month
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
  • Seed Collecting Month
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
  • Sowing Month
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
  • Cutting Month
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Propagation Method
Specialist Method

Seed Information

Seed Collection

Collect spores when mature on the frond. Unripe sori are generally light green then change to yellowish-brown and to dark brown or black when mature. Place fronds, or portions of fronds, containing ripe spores in a paper bag and leave in a dry and draught-free place. Spores should begin to release immediately and all spores are released within days unless the species has tough, leathery fronds. Some species produce large quantities of spores from one frond, others require many fronds to produce similar quantities. Fertile segments similar to sterile ones.

Seed Treatment Notes

Use a moisture-retaining medium and a pot that allows drainage. Sterilise medium and container with boiling water. Sow spores by sprinkling a small amount onto the surface of the medium. Cover immediately with clean glass or plastic wrap. Leave in a warm area in strong, but not direct, sunlight. Specks of green appear after 2-4 weeks. These are the young prothalli. During the next 6-12 months they are at risk from overcrowding and pathogens. When the first fronds appear the sporelings can be slowly hardened by gradual removal of the container cover. Take care to avoid drying out. Prick out sporelings when the second frond appears.

Germination Time

2-4 weeks

Cutting & Division Information

Ferns producing stolons such as Blechnum species can be propagated by removing offsets from the subterranean stolons. This method has a high success rate.