Seeds of South Australia
Cyperus difformis (Cyperaceae)
Variable Flat-sedge
List of species for Cyperus
Click on an image to enlarge it
Seed collecting:
March to September
Herbarium regions:
North Western, Lake Eyre, Gairdner-Torrens, Flinders Ranges, Eastern, Murray
NRM regions:
Alinytjara Wilurara, Northern and Yorke, South Australian Arid Lands, South Australian Murray-Darling Basin
IBRA regions
SUMMARY
Southern Flinders (FLB04)Flinders Lofty Block
 Rare   (IUCN: RA d(ii))   [spread by birds; ephemeral]
Central Flinders (FLB06) 
 Vulnerable   (IUCN: VU D2)   [needs sandy soil]
South Olary Plain (MDD01)Murray Darling Depression
 Rare   (IUCN: RA d(ii))   [comes up after floods in depressions; can lie dormant]
Murray Mallee (MDD02) 
 Rare   (IUCN: RA d(i,ii))   (Probable Decline)   [restricted to river area]
Murray Scroll Belt (RIV06)Riverina
 Least Concern   [restricted to river area]
Arcoona Plateau (GAW04)Gawler
 Rare   (IUCN: RA d(ii))   [sthn limit, variable trend]
Torrens (GAW06) 
 Vulnerable   (IUCN: VU D2)   [limited habitat]
Roxby (GAW07) 
 Least Concern
Commonwealth Hill (GAW08) 
 Near Threatened
Bimbowrie (BHC05)Broken Hill Complex
 Rare   (IUCN: RA d(ii))   [spread by birds; ephemeral]
Strzelecki Desert (SSD05)Simpson Strzelecki Dunefields
 Least Concern
Breakaways (STP01)Stony Plains
 Rare   (IUCN: RA d(ii))
Oodnadatta (STP02) 
 Near Threatened
Murnpeowie (STP03) 
 Least Concern
Macumba (STP05) 
 Near Threatened
Witjira (STP06) 
 Near Threatened
Baltana (STP07) 
 Least Concern
Sturt Stony Desert (CHC02)Channel Country
 Least Concern
Coongie (CHC06) 
 Least Concern
Lake Pure (CHC07) 
 Least Concern
Mann-Musgrave Block (CER01)Central Ranges
 Near Threatened
IBRA regions
DISPLAY ALL
2 of 6 subregionsFlinders Lofty BlockRare
, Vulnerable
2 of 6 subregionsMurray Darling DepressionRare
Murray Scroll Belt (RIV06)RiverinaLeast Concern
  [restricted to river area]
4 of 8 subregionsGawlerLeast Concern
, Near Threatened
, Rare
, Vulnerable
Bimbowrie (BHC05)Broken Hill ComplexRare
  (IUCN: RA d(ii))   [spread by birds; ephemeral]
Strzelecki Desert (SSD05)Simpson Strzelecki DunefieldsLeast Concern
6 of 7 subregionsStony PlainsLeast Concern
, Near Threatened
, Rare
3 of 4 subregionsChannel CountryLeast Concern
Mann-Musgrave Block (CER01)Central RangesNear Threatened
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. Difformis from the Latin 'difformis' meaning changing shape.
Distribution:
Found in the north-east part of South Australia and along the Murray river, growing in seasonally wet, open situations, often in disturbed sites. Also found in all mainland states.
Status:
Native. Common in South Australia. Common in the other states.
Plant description:
Tufted annual to 50 cm high. Leaves grass-like, shorter than stems to 5 mm wide. Inflorescence a simple umbel or reduced to a dense head. Spikelets usually reddish-black, 8-20 flowered, small, linear 4-8mm long, 0.75mm wide. Flowering between January and July.
Fruit type:
Flat, red-brown fruit-head in dense clusters.
Seed type:
Pale brown ovoid triangular seed to 0.5 mm long and 0.4 mm wide, with a wrinkled surface.
Embryo type:
Capitate.
Seed collecting:
Collect fruits either by picking off the mature heads, those turning an red-brown colour and come-off easily or pull out the whole plant.
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. Be careful, as the seeds are very small. Seeds are yellowish ovoid and hard. 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 three collections, the seed viability were high, ranging from 95% to 100%.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA8600 (0.27 g)40-5026-Sep-2007DJD870
Lake Eyre
19-Sep-200895%-18°C
BGA2500 (0.74 g)4011-Mar-2007RJB70920
Gairdner-Torrens
19-Sep-2008100%-18°C
BGA13600 (0.4 g)20+12-Aug-2010TST962
Lake Eyre
1-Jan-2012100%-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.