Common names
Cassia Wattle
Senna 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. Praemorsa from the Latin 'praemorsus' meaning as if bitten off?, referring to the praemorse, or truncate leaf tip.
Distribution and status
Endemic to South Australia and found on north-eastern Eyre Peninsula between Cleve and Cowell. Native. Rare in South Australia.
Herbarium region: Eyre Peninsula
AVH map: SA distribution map (external link)
Plant description
Shrub to 3 m tall; erect, glabrous, suckering. Leaves linear to 9 cm long and 2.5 mm wide; flattened, slightly to strongly incurved, soft and flexible; 1-veined with a single vein submerged and not readily visible with some longitudinal wrinkling on drying; apex obliquely terminated by brown resinous gland flanked by two minute stipule-like appendages and exceeded by an ecentric incurved, swollen, short, mucro. Flower-spike 1 or rarely 2 reduced racemes per node, with globular, bright lemon-yellow flower-heads. Flowering between October and December. Fruits are brown, linear, straight or slightly curved, flat or twisted pod to 13 cm long and 8.5 mm wide; glabrous, somewhat raised over the seeds and constricted between them. Seeds are hard, dark black elliptic to ovoid seed to 6.5 mm long and 4 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. 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 |
|---|---|---|---|---|---|---|---|
| MSB | 1,400 (35.22 g) | 100+ | 20-Nov-2007 | PJL2612 Eyre Peninsula | 65% |
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.