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. Menzelii named in honour of O. E. Menzel, a botanical collector, who first collected this species in flower in 1897, at Monarto, South Australia.
Distribution and status
Endemic to South Australia and found in a small area in the Murray region near Monarto and in the Flinders Ranges. Occurs in open scrub, often associated with Eucalyptus socialis and E. incrassata, on grey-brown calcareous loamy soils. Native. Very rare in South Australia.
Herbarium regions: Flinders Ranges, Murray
NRM regions: Northern and Yorke, South Australian Murray-Darling Basin
AVH map: SA distribution map (external link)
Erect, compact, rounded spreading shrubs to 2 m high, branching near ground level into a number of ascending stems. Leaves terete or subterete to 3.5 cm long and approximately 1 mm wide. Inflorescences simple and axillary, solitary or twin with globular, bright yellow flower-heads. Flowering from July to October. Fruits are brown linear pod to 14.5 cm long and 3 mm wide; curved or slightly twisted; biconvex, contracted and acute at both ends with yellowish vein-like margins constricted between seeds. Seeds are hard black ellipsoid seed to 5 mm along and 2 mm wide with a large fleshy, whitish aril. Seed embryo type is investing.
Seed collection and propagation
Collect seeds between November 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 six collections, the seed viability was high, ranging from 70% to 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|
|BGA||651 (1.7 g)||43||17-Dec-2003||PJA66|
|BGA||1,289 (4.67 g)||52||17-Dec-2003||PJA69|
|5,500 (51.6 g)|
5,500 (51.6 g)
|BGA||7,900 (63.33 g)||8-Dec-2005||CO4|
|8,000 (61.07 g)|
8,000 (61.07 g)
|BGA||3,000 (13.16 g)||100+||8-Dec-2009||KHB334|
|Date||Result||T0||T50||Pre-treatment | Germination medium | Incubator: Photoperiod / Thermoperiod|
|Apr-10||100%||7||14||seed coat nicked with scalpel;|
12/12; / 20Â°C
|Apr-10||98%||7||14||seed coat nicked with scalpel;|
Incubated under spring/autumn conditions
Incubated under winter conditions