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. Araneosa from the Latin 'araneosus' meaning cobweb-like, referring to the cobwebby appearance of the tree, due to the mesh of long fine branches and leaves.
Distribution and status
Endemic to South Australia. Found on hillsides and ridges and restricted to a small area in the Flinders Ranges region (northern part) from Nudlamutana Well near Balcanoona along the ranges to Arkaroola. Native. Very rare in South Australia.
Herbarium region: Flinders Ranges
NRM region: South Australian Arid Lands
AVH map: SA distribution map (external link)
Small, erect, wispy trees to 8 m high, with a cobwebby in appearance. Bark smooth, grey but becoming reddish-brown on young branches. Leaves slender, glabrous, light green to 35 cm or sometimes to 69 cm long and to 1.8 mm diameter with curved tips. Small gland situated near leaf base. Inflorescences axillary racemes with globular, yellow flower-heads. Flowers irregular periods throughout the year. Fruits are long brown, slightly curved pods to 15 cm long and 6 mm wide, with prominent vein-like margins and constricted between the seeds. Seeds are hard black ovoid seeds to 5 mm long and 3 mm wide with a long orange aril. 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. From one collection, the seed viability was high, at 100%. 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|
|990 (15.88 g)|
990 (15.88 g)
|BGA||14,900 (268.85 g)||27-Oct-2011||KHB605|