Seeds of South Australia
Acacia rigens (Leguminosae)
Needlebush Wattle
List of species for Acacia
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Seed collecting:
November to December
Herbarium regions:
North Western, Nullarbor, Gairdner-Torrens, Flinders Ranges, Eyre Peninsula, Northern Lofty, Murray, Yorke Peninsula, Southern Lofty, South Eastern
NRM regions:
Adelaide and Mount Lofty Ranges, Alinytjara Wilurara, Eyre Peninsula, Northern and Yorke, South Australian Arid Lands, South Australian Murray-Darling Basin, South East
IBRA regions
SUMMARY
Tintinara (NCP04)Naracoorte Coastal Plain
 Least Concern   [edge of range]
Fleurieu (KAN02)Kanmantoo
 Rare   (IUCN: RA d(ii))   [edge of range]
Broughton (FLB02)Flinders Lofty Block
 Least Concern   (Probable Decline)
Olary Spur (FLB03) 
 Least Concern
Southern Flinders (FLB04) 
 Rare   (IUCN: RA d(i))   [Naturally rare in SF]
Northern Flinders (FLB05) 
 Rare   (IUCN: RA d(ii))
Central Flinders (FLB06) 
 Rare   (IUCN: RA d(ii))
Southern Yorke (EYB01)Eyre Yorke Block
 Near Threatened   (Probable Decline)
St Vincent (EYB02) 
 Near Threatened   (Probable Decline)
Eyre Hills (EYB03) 
 Least Concern   [salt tolerant]
Talia (EYB04) 
 Least Concern   [salt tolerant]
Eyre Mallee (EYB05) 
 Least Concern   [salt tolerant]
South Olary Plain (MDD01)Murray Darling Depression
 Least Concern
Murray Mallee (MDD02) 
 Least Concern
Murray Lakes and Coorong (MDD03) 
 Near Threatened   [edge of range; likes mallee]
Lowan Mallee (MDD04) 
 Least Concern
Wimmera (MDD05) 
 Near Threatened   [edge of range]
Murray Scroll Belt (RIV06)Riverina
 Least Concern
Myall Plains (GAW01)Gawler
 Least Concern   [salt tolerant]
Gawler Volcanics (GAW02) 
 Least Concern   [salt tolerant]
Gawler Lakes (GAW03) 
 Least Concern   [salt tolerant]
Arcoona Plateau (GAW04) 
 Rare   (IUCN: RA d(i,ii))   [salt tolerant]
Kingoonya (GAW05) 
 Rare   (IUCN: RA d(i,ii))   [salt tolerant]
Kintore (GVD04)Great Victoria Desert
 Rare   (IUCN: RA d(i,ii))   [limestone plains, localised, outliers]
Yellabinna (GVD06) 
 Least Concern   [salt tolerant]
Mann-Musgrave Block (CER01)Central Ranges
 Rare   (IUCN: RA d(i,ii))   [limited habitat]
Watarru (CER02) 
 Rare   (IUCN: RA d(i,ii))   [limited habitat]
IBRA regions
DISPLAY ALL
Tintinara (NCP04)Naracoorte Coastal PlainLeast Concern
  [edge of range]
Fleurieu (KAN02)KanmantooRare
  (IUCN: RA d(ii))   [edge of range]
5 of 6 subregionsFlinders Lofty BlockLeast Concern
, Rare
5 of 5 subregionsEyre Yorke BlockLeast Concern
, Near Threatened
5 of 6 subregionsMurray Darling DepressionLeast Concern
, Near Threatened
Murray Scroll Belt (RIV06)RiverinaLeast Concern
5 of 8 subregionsGawlerLeast Concern
, Rare
2 of 4 subregionsGreat Victoria DesertLeast Concern
, Rare
2 of 3 subregionsCentral RangesRare
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 Acacia]
Name derivation:
Acacia from the Greek 'akakia' and derived from 'ake' or 'akis' meaning a sharp point or thorn and 'akazo' meaning to sharpen. Dioscorides, the Greek physician and botanist used the word in the 1st century AD for the Egyptian thorn tree, Acacia arabica. Rigens from the Latin 'rigens' meaning stiff or rigid, referring to the stiff unbending needle-like phyllodes.
Distribution:
Found in sandy alkaline yellow duplex, dark or grey-brown calcareous loamy earths, or brown calcareous earths on Eyre Peninsula, Yorke Peninsula, Mount Lofty Ranges, Flinders Ranges, Murray and the upper South-eastern. Also found in Western Australia, Queensland, New South Wales and Victoria.
Status:
Native. Common in South Australia. Common in the other states.
Plant description:
Erect, spreading, much-branched, glabrous or minutely hairy shrubs to 3 m high, sometimes developing a small tree-like form and attaining heights of 6 m. Leaves linear to 13 cm long and 2.5 mm wide. Inflorescences simple and axillary, solitary or twin, sometimes in clusters up to 4 heads with globular, mid-yellow flower-heads. Flowering between July and December.
Fruit type:
Long, curved, brown pods to 7 cm long and 3 mm wide.
Seed type:
Dark brown ellipsoid seeds to 3 mm long and 2 mm wide.
Embryo type:
Investing.
Seed collecting:
Collect mature pods that are turning brown, with hard, dark seeds inside.
Seed cleaning:
Place the pods in a tray and leave to dry for 1-2 weeks or until the pods begin to split. Then rub the dried pods 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 average, at 50%.
Seed germination:
This species has physical dormancy that needs to be overcome for the seed to germinate (e.g. nicking or softening the seed coat).
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA40200 (112.6 g)40-506-Dec-2005DJD285
Eyre Peninsula
1-Aug-200650%-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.