Common names
Cowell Spine-bush
Six-nerve Spine-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. Hexaneura from the Greek 'hex' meaning six and 'neuron' meaning a nerve, referring to the six veins on the phyllodes.
Distribution and status
Endemic to South Australia and confined to north-eastern Eyre Peninsula between Kimba and Cowell. Found on well-drained gravelly loams and sands, on small quartzite hills with associated limestone or ironstone deposits. Native. Rare in South Australia.
Herbarium region: Eyre Peninsula
AVH map: SA distribution map (external link)
Plant description
A rigid, prickly roughly rounded shrub, rarely over 1m high to 2 m wide. Leaves sessile, perpendicular, rigid, straight or slightly recurved, compressed to 17 mm long and 2 mm wide, distinctly 6-veined (one on each margin and two on each face), with veins strongly raised in well-defined ridges, abruptly tapered into a rigid mucro 1-2mm long. Inflorescence simple, axillary with globular, golden-yellow flower-heads. Flowering between July and September Fruits are linear, undulate and irregularly bent or folded pods to 9 cm long to 3 mm wide, sparsely pubescent towards base and often persisting as a tangled mass, Seeds are hard, dark brown, elliptic to ovoid seed to 3 mm long to 2 mm wide. Seed embryo type is investing.
Seed collection and propagation
Collect seeds between November and January. Collect mature pods that are turning brown, with hard, dark seeds inside. Be careful when collecting the pods as the plant is very prickly. 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 MSB | 2,000 (13.77 g) 2,000 (13.77 g) | 6 | 20-Nov-2007 | TST237 Eyre Peninsula | 1-May-2019 | 90% | -18°C |
| BGA | 3,700 (25.35 g) | 30 | 7-Dec-2018 | JRG711 Eyre Peninsula | 24-Jun-2020 | 80% | -18°C |
| BGA | 33,320 (235.900 g) | 25+ | 14-Dec-2022 | BKB162 Eyre Peninsula | 20-Jun-2023 | 90% | -18°C, -80°C |
| BGA | 9,855 (54.810 g) | 40+ | 13-Dec-2022 | BKB154 Eyre Peninsula | 20-Jun-2023 | 100% | -18°C, -80°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.