Seeds of South Australia
Acacia rivalis (Leguminosae)
Creek Wattle
List of species for Acacia
Display more images
Click on an image to enlarge it
Seed collecting:
November to December
Herbarium regions:
Lake Eyre, Gairdner-Torrens, Flinders Ranges, Eastern
NRM region:
South Australian Arid Lands
IBRA regions
Northern Flinders (FLB05)Flinders Lofty Block
 Least Concern
Central Flinders (FLB06) 
 Least Concern
Murnpeowie (STP03)Stony Plains
 Rare   (IUCN: RA d(i,ii))   [edge of range]
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  rom the Greek 'akakia' and derived rom '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 or Egyptian thorn tree, Acacia arabica. Rivalis rom the Latin 'rivalis' meaning growing by streams.
Distribution:
Endemic to South Australia and is confined to northern Flinders Ranges, growing in tall shrubland on ridges and rocky shaly hillsides or along watercourses.
Status:
Native. Common in South Australia.
Plant description:
Small, parachute-shaped trees or shrubs to 4 m high with a dense domed canopy branching near the ground, or with a single trunk for more or less 1 m before dividing into a number branches. Branchlets reddish and slightly angular. Leaves linear lanceolate to 14 cm long and 5 mm wide; falcate, narrowed towards the base, glabrous and shiny when fresh, with prominent central vein to a short curved apex. Small glands on upper margin at least 15mm above the base. Inflorescences axillary racemes, solitary with small, globular yellow lower-heads. Flowering between May and November.
Fruit type:
Smooth, brown, linear pod to 12 cm long and 5 mm wide, straight or curved.
Seed type:
Hard, black, semi-flat, ellipsoid seed 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 or 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 85%.
Seed germination:
This species has physical dormancy that needs to be overcome or the seed to germinate (e.g. nicking or softening the seed oat).
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA860 (24.96 g)20023-Nov-2009KHB318
Flinders Ranges
Jun-201085%-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.