Seeds of South Australia
Cyperus bifax (Cyperaceae)
Down's Nut-grass
List of species for Cyperus
Click on an image to enlarge it
Seed collecting:
May to October
Herbarium regions:
Lake Eyre, Flinders Ranges
NRM region:
South Australian Arid Lands
IBRA regions
Murnpeowie (STP03)Stony Plains
 Rare   (IUCN: RA d(ii))
Witjira (STP06) 
 Rare   (IUCN: RA d(ii))
Baltana (STP07) 
 Rare   (IUCN: RA d(ii))
Coongie (CHC06)Channel Country
 Rare   (IUCN: RA d(ii))
RSCA map:
Regional Species Conservation Assessments per IBRA subregion. Please click the thumbnail map.
AVH map:
Australian distribution map (external link)
SA Census:
Census of South Australian plants (external link)     [genus Cyperus]
Name derivation:
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. Bifax from the Latin 'bifax' meaning with two faces, alluding to the species similarity to other Cyperus species.
Found scattered in north-east South Australia growing on floodplains on heavy clay soils. Also found in all mainland States.
Native. Rare in South Australia. Rare in Victoria. Common in the other States.
Plant description:
Perennial sedge to 75 cm high with wiry rhizomes bearing prominent, ellipsoid, fibrous-coated tubers. Stems slender, triquetrous throughout. Leaves grass-like, narrow, usually shorter than the stems; bracts 2-4, the lower about as long as or longer than the inflorescence. Inflorescence a simple umbel with 4-8 slender rigid rays. Spikelets brown with 12-24 flowers, close together in small spikes of 3-10. Flowering between April and August.
Fruit type:
Orange fruit-head in loose clusters at the tips of erect triangular stems.
Seed type:
Brown ovoid triangular seed to 1.5 mm long and 1 mm wide, with fine creamy reticulate outer coating.
Embryo type:
Seed collecting:
Collect fruits by picking off the mature heads, those turning an orange colour and come-off easily.
Seed cleaning:
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.
Seed viability:
From one collection, the seed viability was high, at 100%.
Seed germination:
Seeds are non-dormant, viable seed should germinate readily.
Seeds stored:
LocationNo. of seeds
(weight grams)
of plants
Collection number
Collection location
% ViabilityStorage
BGA6500 (2.16 g)1011-May-2008RJB77863
Lake Eyre
19-Sep-2008100%+5°C, -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.