Plants of
South Australia
Acacia argyrophylla
Fabaceae
Silver Mulga,
Silver Mulga-bush
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Regional Species Conservation Assessments per IBRA subregion.
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Near threatened
Rare
Vulnerable
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Extinct
Data deficient
Adelaide
Arkaroola
Ceduna
Coober Pedy
Hawker
Innamincka
Marla
Marree
Mount Gambier
Oodnadatta
Renmark
Wudinna
Keith
Yunta
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Botanical art

Kath Alcock paintings: 7

Prior names

Acacia bombycina

Acacia brachybotrya var. argyrophylla

Acacia brachybotrya f. argyrophylla

Common names

Silver Mulga

Silver Mulga-bush

Etymology

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 and status

Endemic to South Australia 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. Native. Locally common in South Australia.
Herbarium regions: Flinders Ranges, Eastern, Northern Lofty, Yorke Peninsula, Southern Lofty, Green Adelaide
NRM regions: Adelaide and Mount Lofty Ranges, Alinytjara Wilurara, Northern and Yorke
AVH map: SA distribution map (external link)

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 and 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. Fruits are 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. Seeds are hard, black, elliptical to ovoid to 7 mm long and 4.5 mm wide. Seed embryo type is investing.

Seed collection and propagation

Collect seeds between October and December. Collect mature pods that are turning brown with hard, dark seeds inside. 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 is usually high. 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:
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LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA 
MSB
3,335 (236.7 g)
3,335 (236.7 g)
1917-Dec-2003PJA67
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:
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