Scientific Name: Gahnia filum

Common Name: chaffy sawsedge

Family Classification (Clade): Monocots

Family: Cyperaceae

Form Description: Densely tufted sedge with long, in rolled leaves with fine wavy tips.

Flowers: Many clustered flowers in a dense, bristly flower head up to 60cm long.

Fruit: Nut – triangular and rusty-brown when mature, 5-6mm long.

Municipality
Break O’DayBrightonBurnieCentral CoastCentral HighlandsClarenceDevonportDorsetFlindersGeorge TownGlamorgan-Spring BayHobartKingboroughLatrobeLauncestonNorthern MidlandsSorellTasmanWest CoastWest Tamar
Plant Communities
SaltmarshSedgeland and Wetland
Habitat Notes

In saline or brackish habitats; coastal creek and river edges, saltmarshes and flats near sea level, and up to 200m altitude inland where saline.

General Notes

Requires moist, sandy soil in a sunny position. This species is common in the wetland flats at Lauderdale and Pittwater in the south-east, and helps provide habitat for migratory birds. A host plant of the chrysotricha skipper butterfly (Hesperilla chrysotricha), also known as the golden haired sedge-skipper. The butterflies twist the leaves together in a spiral to form a shelter.

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
Seed

Seed Information

Seed Collection

Most of the seed will remain held in the seed head for at least a month. Cut the seed heads with secateurs and allow to dry, then vigorously thresh against a hard surface to extract seed.

Seed Treatment Method

Bog Method The seeds of many wetland species need to be kept wet to germinate. Punch a hole in the side of a recycled polyfoam box so that it holds water to the required depth. Sit the tubes in the box to germinate. Once germinated, punch holes in the bottom of the box to allow drainage.

Seed Treatment Notes

Cover seed lightly. Requires 12 months of storage. Smoke, acid treatment or scarification may improve results. Germinates readily from seed.

Cutting & Division Information

Division of Gahnia species tends to have little success.