Plants of
South Australia
Bolboschoenus caldwellii
Salt Club-sedge
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Regional Species Conservation Assessments per IBRA subregion.
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Botanical art

Kath Alcock paintings: 5.


Bolboschoenus from the Greek 'bolbos' meaning a bulb and 'Schoenus' a genus of Cyperaceae from which it was considered separable by the swellings on the stem. Caldwellii named after A. C. Caldwell, of Hamilton, for many years an enthusiastic collector and student of our indigenous flora and who did much to stimulate the writer's interest in New Zealand's plants.

Distribution and status

Found in fresh or brackish water across the eastern side of South Australia. Also found in all other states. Native. Common in South Australia. Rare in Northern Territory. Common in all the other States.
Herbarium regions: Lake Eyre, Flinders Ranges, Eastern, Eyre Peninsula, Northern Lofty, Murray, Southern Lofty, South Eastern
NRM regions: Adelaide and Mount Lofty Ranges, Eyre Peninsula, South Australian Arid Lands, South Australian Murray-Darling Basin, South East
AVH map: SA distribution map (external link)

Plant description

Rhizome creeping sedge to 90 cm high with hard ovoid tubers and three-sided stems. Leaves flat and grass-like. Inflorescence umbel-like, with 1-3 rays erect or spreading, or reduced to 1 or 2 golden- or red-brown spikelets. Fruits are dense red-brown clusters of fruiting heads. Seeds are brown ovoid nut to 3 mm long and 2.5 mm wide, smooth, shiny and covered with a fine mesh-like surface. Seed embryo type is capitate.

Seed collection and propagation

Collect seeds between October and March. Collect whole heads that are brown, containing golden hard seeds. 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. From one collection, the seed viability was high, at 85%.

Seeds stored:
LocationNo. of seeds
(weight grams)
of plants
Collection number
Collection location
% ViabilityStorage
30,100 (102.5 g)
30,100 (102.5 g)
Southern Lofty
Location: BGA — the seeds are stored at the Adelaide Botanic Gardens, MSB — the seeds are stored at the Millennium Seed Bank, Kew, England.
Number of plants: This is the number of plants from which the seeds were collected.
Collection location: The Herbarium of South Australia's region name.
% Viability: Percentage of filled healthy seeds determined by a cut test or x-ray.