Botanical art
Prior names
Racosperma adsurgens
Common names
Whipstick Wattle
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. Adsurgens mean to become erect.erect, referring to the species' erect habit.
Distribution and status
Found only in a small area in the far northeast of South Australia. Grows in reddish sandy and gravelly soils, on plains and hillsides, commonly in spinifex grassland communities. Also found in Western Australia, Northern Territory and Queensland. Native. Rare in South Australia. Common in the other States.
Herbarium region: Lake Eyre
AVH map: SA distribution map (external link)
Plant description
Shrub or small tree to 4 m high. Bark smooth then splitting or fibrous, grey-brown, reddish beneath. Phyllodes linear, straight or upwardly curved, flat to 18 cm long and 4.5mm wide, glabrous, resinous, particularly when young. Inflorescences axillary, solitary with clylindrical, yellow flower-heads. Flowering between May and September, sometimes as early as Feb. Fruits are light brown, linear pod to 12cm long and 3.5mm wide, straight or slightly curved, slightly raised over and constricted between seeds, with no prominent margins. Seeds are hard, dark drown to black ovoid seed to 5 mm long and 2.5 mm wide. Seed embryo type is investing.
Seed collection and propagation
Collect seeds between October and November. 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. From one collection, the seed viability was high, at 90%. This species has physical dormancy that needs to be overcome for the seed to germinate (e.g. nicking or softening the seed coat).
| Location | No. of seeds (weight grams) | Number of plants | Date collected | Collection number Collection location | Date stored | % Viability | Storage temperature |
|---|---|---|---|---|---|---|---|
| BGA | 1,600 (18.08 g) | 20+ | 25-Oct-2007 | DJD922 Lake Eyre | 19-Sep-2008 | 90% | -18°C |
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.