Plants of
South Australia
Cyperus gilesii
Cyperaceae
Giles' Flat-sedge
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Adelaide
Arkaroola
Ceduna
Coober Pedy
Hawker
Innamincka
Marla
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Keith
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Botanical art

Kath Alcock paintings: 3

Etymology

Cyperus from the Latin 'cyperos' and derived from the Greek 'kypeiros', an ancient Greek name used by Homer and Theophrastus for several plants of this genus. Gilesii named after William Ernest Powell Giles (1835-1897), an Australian explorer who led five major expeditions in central Australia.

Distribution and status

Found in the north and north-east part of South Australia growing in ephemerally wet situations such as inland stream banks. Also found in Western Australia, Northern territory, Queensland and New South Wales. Native. Common in South Australia. Rare in Western Australia. Common in the other States.
Herbarium regions: North Western, Lake Eyre, Gairdner-Torrens, Flinders Ranges, Eastern
NRM regions: Alinytjara Wilurara, South Australian Arid Lands
AVH map: SA distribution map (external link)

Plant description

Slender annual sedge to 30 cm high. Stems usually tufted, erect, slender; trigonous, smooth but prominently striate. Leaves shorter than the stems, 1-4.5 mm wide, margins sparsely scabrous; bracts 2-4, leaf-like, the lower longer or much longer than the inflorescence. Flower-spike a simple umbel or reduced to a head, the rays up to 5 in number; slender but rigid, to 6 cm long; spikelets approximate but not quite digitate, few to several on each ray; bright-brown, chestnut, or golden-brown, 15-30-flowered; lanceolate to linear, rather acute, very flat, c. 10-30 mm long, 2.5-4.5 mm wide; rhachilla wingless or nearly so; glumes rather dense but soon spreading and their margins inrolled; 4-5 mm long, prominently nerved with a finally recurved mucro to 1 mm long; style 3-branched. Flowering between September and April. Fruits are flat, golden brown fruit-head in dense clusters. Seeds are brown long oblong seed to 5 mm long and 1 mm wide. Seed embryo type is capitate.

Seed collection and propagation

Collect seeds between January and December. Collect fruits by picking off the mature heads, those turning golden brown and come-off easily. 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 two collections, the seed viability was high, ranging from 90% to 95%.

Seeds stored:
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LocationNo. of seeds
(weight grams)		Number
of plants		Date
collected		Collection number
Collection location		Date
stored		% ViabilityStorage
temperature
BGA2,700 (0.93 g)2011-Aug-2010DJD1848
Lake Eyre		1-Jan-201295%-18°C
BGA10,900 (8.43 g)50+12-Aug-2010TST961
Lake Eyre		1-Jan-201290%-18°C
BGA22,000 (3.88 g)50+21-Sep-2016DJD3449
Lake Eyre		1-Nov-201785%-18°C
BGA 
MSB		5,600 (1.4 g)
5,600 (1.4 g)		30+15-Oct-2016JRG494
Lake Eyre		1-Nov-201790%-18°C
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.
Germination table:
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We acknowledge the contributions of the South Australian Seed Conservation Centre, the Botanic Gardens of South Australia, and the Department for Environment and Water.