Plants of
South Australia
Gahnia hystrix
Cyperaceae
Kangaroo Island Spiky Saw-sedge,
Spiky Saw-sedge,
Kangaroo Island Saw-sedge
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Botanical art

Kath Alcock painting: 1

Common names

Kangaroo Island Spiky Saw-sedge

Spiky Saw-sedge

Kangaroo Island Saw-sedge

Etymology

Gahnia named after Dr. Henricus Gahn, 19th century Swedish botanist and student of Linnaeus. Hystrix from Greek meaning a hedgehog, alluding to the spiky habit of the species.

Distribution and status

Endemic to South Australia and found only on the western side of Kangaroo Island, growing on limestone along the coast. Native. Rare in South Australia.
Herbarium region: Kangaroo Island
AVH map: SA distribution map (external link)

Plant description

Low dense spiky sedge to 15 cm high. Leaf blades terete and more or less channelled; smooth, rigid, pungent-pointed, erect, to 7 cm long and 0.5 mm wide. Inflorescence a small spike-like panicle, much shorter and almost concealed by the leaves, pale brown. Flowering between November and January. Fruits are dark brown spike. Seeds are yellowish brown three sided ovoid seed to 3 mm long and 1.7 mm wide, shiny. Seed embryo type is capitate.

Seed collection and propagation

Collect heads that are dying off, turning dark brown and containing hard seeds. Be very careful when collecting as the heads are sometime hidden among the spiky leaves. Place the heads in a tray and leave to dry for one to two weeks. Then rub the heads with a rubber bung to dislodge the seeds. Use a sieve to separate any unwanted material. Store the seeds with a desiccant such as dried silica beads or dry rice, in an air tight container in a cool and dry place.