Seeds of South Australia
Acacia brachybotrya (Leguminosae)
Grey Wattle
List of species for Acacia
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Seed collecting:
October to January
Herbarium regions:
Nullarbor, Flinders Ranges, Eyre Peninsula, Northern Lofty, Murray, Yorke Peninsula, Southern Lofty, Kangaroo Island, South Eastern
NRM regions:
Adelaide and Mount Lofty Ranges, Alinytjara Wilurara, Eyre Peninsula, Kangaroo Island, Northern and Yorke, South Australian Arid Lands, South Australian Murray-Darling Basin, South East
IBRA regions
SUMMARY
Tintinara (NCP04)Naracoorte Coastal Plain
 Rare   (IUCN: RA d(ii))   [most popns. on roadsides]
Kangaroo Island (KAN01)Kanmantoo
 Vulnerable   (IUCN: VU D2)   [a number of pops are in reserves]
Fleurieu (KAN02) 
 Vulnerable   (IUCN: VU D1+2)   (Probable Decline)   [Martin O'Leary, Tim Croft felt it should be RA d(ii) edge of range; has good capability to regenerate; P Lang: VU; only found on roadsides]
Southern Yorke (EYB01)Eyre Yorke Block
 Rare   (IUCN: RA d(i))   (Definite Decline)   [Hybridises with A. argyrophylla. Fragmented]
St Vincent (EYB02) 
 Rare   (IUCN: RA b)   (Definite Decline)   [Hybridising, roadside plants. Taxonomic issues]
Eyre Hills (EYB03) 
 Rare   (IUCN: RA d(i,ii))   (Probable Decline)   [land clearance]
Talia (EYB04) 
 Least Concern
Eyre Mallee (EYB05) 
 Least Concern
South Olary Plain (MDD01)Murray Darling Depression
 Least Concern
Murray Mallee (MDD02) 
 Least Concern
Murray Lakes and Coorong (MDD03) 
 Rare   (IUCN: RA d(i,ii))   (Probable Decline)   [most popns. on roadsides]
Lowan Mallee (MDD04) 
 Rare   (IUCN: RA a)   (Probable Decline)   [taxo issues, poss different spp]
Murray Scroll Belt (RIV06)Riverina
 Rare   (IUCN: RA d(ii))   (Probable Decline)   [limited habitat, not part of floodplain veg]
Maralinga (GVD03)Great Victoria Desert
 Rare   (IUCN: RA d(i,ii))
Yalata (NUL03)Nullarbor
 Rare   (IUCN: RA d(i,ii))
IBRA regions
DISPLAY ALL
Tintinara (NCP04)Naracoorte Coastal PlainRare
  (IUCN: RA d(ii))   [most popns. on roadsides]
2 of 2 subregionsKanmantooVulnerable
5 of 5 subregionsEyre Yorke BlockLeast Concern
, Rare
4 of 6 subregionsMurray Darling DepressionLeast Concern
, Rare
Murray Scroll Belt (RIV06)RiverinaRare
  (IUCN: RA d(ii))   (Probable Decline)   [limited habitat, not part of floodplain veg]
Maralinga (GVD03)Great Victoria DesertRare
  (IUCN: RA d(i,ii))
Yalata (NUL03)NullarborRare
  (IUCN: RA d(i,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 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. Brachybotrya from the Greek 'brachys' meaning short and  'botrys' meaning a spike, referring to the flower on a short penduncle.
Distribution:
Found across most of South Australia except the more arid part, in open-scrub mallee vegetation and open woodland on a variety of soils. Also found in New South Wales and Victoria.
Status:
Native. Common in South Australia. Common in the other states.
Plant description:
Compact, dense, rounded, spreading, grey-green shrubs to 3 m high and often the same or more across. Leaves obliquely oblanceolate to obovate to 3.5 cm long to 15 mm wide, flat, grey-green, glabrous or silky-hairy. Inflorescences axillary, solitary or mostly 2-5 globular, bright yellow flower-heads. Flowering from July  to November.
Fruit type:
Long, dark brown, straight or slightly curved pod to 7 cm long and 6 mm wide, raised and sometimes warty.
Seed type:
Dark brown to black, semi-flat ovoid seeds to 7 mm long and 4 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 desicant such as dried silica beads or dry rice, in an air tight container in a cool and dry place.
Seed viability:
Frome one collection, the seed viability was high, at 86%.
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).
Germination table:
DateResultT0T50Pre-treatment | Germination medium | Incubator: Photoperiod / Thermoperiod
June 201298%7d14d The seed coat of each seed was nicked using a scalpel blade
70mm glass petri dishes on 1% w/v agar
Incubated under spring/autumn conditions
Result: Maximum percentage of germination observed.
T0: Number of days before first germinant observed.
T50: Number of days to achieve 50% germination.
Pre-treatment: The initial treatment that the seeds received prior to placement on germination media.
Germination medium: The substrate that seeds were placed on for the duration of the germination experiment.
Incubator conditions:
Photoperiod: The duration of light exposure that the seeds were subject to during a 24 hour period.
Thermoperiod: The constant or diurnal temperatures that seeds were subject to during a 24 hour period.
Winter conditions: 15°C 20 h (3am→11pm); 5°C 4 h (11pm→3am) / 10 h light (8am→6pm); 14 h dark (6pm→8am)
Spring/Autumn conditions: 22°C 12 h (8am→8pm); 10°C 12 h (8pm→8am) / 12 h light (8am→8pm); 12 h dark (8pm→8am)
Summer conditions: 30°C 14 h (6am→8pm); 15°C 10 h (8pm→6am) / 14 h light (6am→8pm); 10 h dark (8pm→6am)