''Gahnia trifida'', the coastal saw-sedge, is a tussock-forming perennial in the family

Cyperaceae The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus ''Carex'' w ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to southern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. A herb, sedge or grass-like, with very rough leaf margins and underside. The species grows in dense tussocks, 1.5 metres and 1 metre across, with leaves over 1 metre long and drooping. It is found on white or grey sand, or clay, that may be saline. The leaf blade is inrolled from the margin on the upper surface. Stems are rigid and erect. Branchlets containing the flowering heads emerge from axils at the main bracts. This branchlet has a spike-like arrangement of numerous, yellow or brown, clusters of flowerheads. The species occurs in wetlands of coastal regions in

Southwest Australia Southwest Australia is a biogeographic region in Western Australia. It includes the Mediterranean-climate area of southwestern Australia, which is home to a diverse and distinctive flora and fauna. The region is also known as the Southwest Aus ...

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

, and

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

. It is found at

Rottnest Rottnest Island ( nys, Wadjemup), often colloquially referred to as "Rotto", is a island off the coast of Western Australia, located west of Fremantle. A sandy, low-lying island formed on a base of aeolianite limestone, Rottnest is an A-class ...

, an island off the west coast, where it grows near the inland salt lakes. The habitat is moist, often adjacent to creeks and swamps, and may also be saline. The first description of ''Gahnia trifida'' was by

Jacques Labillardière Jacques-Julien Houtou de Labillardière (28 October 1755 – 8 January 1834) was a French biologist noted for his descriptions of the flora of Australia. Labillardière was a member of a voyage in search of the Jean-François de Galaup, comte ...

in ''

Novae Hollandiae Plantarum Specimen ''Novae Hollandiae Plantarum Specimen'' is a two-volume work describing the flora of Australia. Facsimiles of the originals can be found in the onlinBiodiversity Heritage Library (Vol.1)anVol 2) The author was the French botanist Jacques Labillar ...

'' (1805).Labillardiere, J.J.H. de (1805), Novae Hollandiae Plantarum Specimen 1(12): 89, t. 116 Type: "in capite Van-Diemen."

References

trifida Flora of South Australia Flora of Tasmania Flora of Victoria (Australia) Poales of Australia Plants described in 1805 Taxa named by Jacques Labillardière {{Australia-plant-stub