Plants of
South Australia
Cyperus alterniflorus
Cyperaceae
Umbrella Flat-sedge
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Regional Species Conservation Assessments per IBRA subregion.
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Adelaide
Arkaroola
Ceduna
Coober Pedy
Hawker
Innamincka
Marla
Marree
Mount Gambier
Oodnadatta
Renmark
Wudinna
Keith
Yunta
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Botanical art

Kath Alcock paintings: 4

Prior names

Mariscus alterniflorus

Common names

Umbrella Flat-sedge

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. Alterniflora from Latin meaning alternating flowers.

Distribution and status

Found in northern South Australia growing in semi-permanent moist situations such as stream banks and rocky gullies. Also found in Western Australia, Northern Territory, Queensland and New South Wales. Native. Common in South Australia. Uncommon in Northern Territory. Common in the other States.
Herbarium regions: Flinders Ranges, Eastern, Eyre Peninsula, Northern Lofty
AVH map: SA distribution map (external link)

Plant description

Erect, tufted perennial sedge to 150 cm high; shortly rhizomatous. Stems stout, trigonous; striate, smooth or scabrous at the top. Leaves mostly longer than the stems, to 12 mm broad, the margins remotely scabrous, keeled. Bracts leaf-like, 3-6, much longer than the inflorescence. Inflorescence compound, the rays 5-8 to 15 cm long but usually much shorter; spikelets in more or less dense globular clusters, reddish or pale-brown, oblong to narrow-ovate compressed, to 17 mm long and 4 mm wide, 6-18-flowered, frequently deciduous as a whole spikelet at maturity. Flowering between August and October. Fruits are red-brown globular fruit-head in clusters at the tip of stems. Seeds are pale brown oblong, triangular seed to 2 mm long and 0.5 mm wide, covered with a thin shiny transparent layer. Seed embryo type is capitate.

Seed collection and propagation

Collect seeds between November and April. Collect fruits by picking off the mature heads, those turning red-brown colour and that 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 80% to 85%. Seeds are non-dormant, viable seed should germinate readily.

Seeds stored:
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LocationNo. of seeds
(weight grams)		Number
of plants		Date
collected		Collection number
Collection location		Date
stored		% ViabilityStorage
temperature
BGA18,000 (5.56 g)1013-Dec-2007RJB76643
Flinders Ranges		19-Sep-200885%-18°C
BGA78,000 (14.66 g)50+2-Apr-2007RJB70981
Flinders Ranges		19-Sep-200880%-18°C
BGA49,000 (22.79 g)50+23-Oct-2011KHB611
Flinders Ranges		1-Jan-201685%-18°C
BGA20,800 (9.697 g)31-Jan-2023CJB10220
Flinders Ranges		20-Jun-202395%-18°C, -80°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.