Seeds of South Australia
Acacia argyrophylla (Leguminosae)
Silver Mulga
List of species for Acacia
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Seed collecting:
October to December
Herbarium regions:
Nullarbor, Flinders Ranges, Eastern, Northern Lofty, Yorke Peninsula, Southern Lofty
NRM regions:
Adelaide and Mount Lofty Ranges, Alinytjara Wilurara, Northern and Yorke
IBRA regions
Fleurieu (KAN02)Kanmantoo
 Near Threatened   [common on roadsides; readily regenerates; land use is changing; Martin O'Leary: slow decline over time; Tim Croft: stable]
Mount Lofty Ranges (FLB01)Flinders Lofty Block
 Vulnerable   (IUCN: VU D2)   [in Onkaparinga area]
Broughton (FLB02) 
 Rare   (IUCN: RA d(ii))   (Definite Decline)   [more roadside plants. DD. Could be other species.]
Olary Spur (FLB03) 
 Rare   (IUCN: RA d(ii))   (Definite Decline)   [grazed, arid, scattered plants DD]
Southern Flinders (FLB04) 
 Rare   (IUCN: RA d(ii))   (Definite Decline)   [grazed, arid, scattered plants DD]
Central Flinders (FLB06) 
 Rare   (IUCN: RA d(i,ii))   [northern edge of range; could be declining]
Southern Yorke (EYB01)Eyre Yorke Block
 Endangered   (IUCN: EN A2ace)   (Definite Decline)   [Hybridises with A. brachybotria]
St Vincent (EYB02) 
 Endangered   (IUCN: EN D)   (Definite Decline)
Murray Mallee (MDD02)Murray Darling Depression
 Least Concern   [west of River]
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. Argyrophylla from the Greek 'argyros' meaning silver and 'phylla' suffix for leaf, referring to the silvery foliage.
Distribution:
Endemic to SA and found in the Flinders Ranges, Mount Lofty Ranges and the bottom of Yorke Peninsula. Grows on low hills and slopes in woodland and mallee, often in alkaline soils. An isolated occurrence from near Cromby, Victoria, is now presumed extinct.
Status:
Native. Locally common in South Australia.
Plant description:
Tall, erect, compact, spreading shrubs to 3 m high often the same or more across, with a golden and silvery appearance. Phyllodes oblanceolate- obovate to 5 cm long and 20 mm wide; flat, covered with short glossy silky, more or less appressed hairs. Young leaves are golden and covered in hairs. Inflorescences axillary, solitary, short racemes with globular, golden yellow flower-heads. Flowering between July and November.
Fruit type:
Dark brown linear pod to 10 cm long and 15 mm broad, raised and often rough and warty over the seeds. Margins yellowish, vein-like, somewhat constricted between the seeds.
Seed type:
Hard, black, elliptical to ovoid seed to 7 mm long and 4.5 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 high, at 100%.
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
BGA 
MSB
3335
3335
1917-Dec-2003PJA 67
Southern Lofty
1-Sep-2004100%+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.
Germination table:
DateResultT0T50Pre-treatment | Germination medium | Incubator: Photoperiod / Thermoperiod
July 2015100%7d7d seed coat nicked
1% water agar
Incubated under spring/autumn conditions
November 200696%11d17d Stored at -18°C (1year). Seed coat nicked with scalpel blade.
Wet filter paper placed over wettex sponge. Irrigated with RO water
Incubated under spring/autumn conditions
March 200490%12d15d Seed sterilised with 20% Hydrogen Peroxide with 3 drops of Tween (10min). Rinsed in sterile water. Seed coat nicked with scalpel blade.
0.8% w/v agar plates
16/8 dark/light  /  20°C Constant
July 20150%NANA None
1% water 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)