Alternative Name(s): False acacia, Locust tree, Yellow locust, Robinia Family: Fabaceae Form: Shrub / Tree Origin: Native to North America Weed Type(s): Weed, Sleeper Weed, Noxious Weed, Naturalised, Introduced garden Escape, Environmental Weed, Cultivation Escape, Alien Escape

Notes: Robinia is a small genus of about twenty species of trees and large shrubs usually with spines on the branches. Leaves have many leaflets giving a fine tracery when viewed upwards. Sweetly perfumed, white pea-like flowers borne in tresses are followed by small brown pods with several seeds.

Black locust produces root suckers when the roots are disturbed and dense clumps may develop crowding out other plants. It was often planted around homesteads and stockyards and sometimes the dense thicket is the living reminder of former farming ventures.

Although native to North America it has become naturalised in Europe forming thickets in disturbed land along roadsides and railways and reducing the view of the surrounding countryside for travellers. It has transformed grassland into open woodland in parts of Germany.

The characteristics which make it weedy have been used to advantage in erosion control work in Hungary. The roots also fix nitrogen in the soil.

Black locust is naturalised in WA, SA, Victoria, NSW and Queensland. It was sometimes planted in Canberra last century as a street tree and is a scattered weed in the ACT. It is still available in nurseries although 'mop top' cultivars are now more popular for small gardens. It is still used as the rootstock however and the problem of suckering has been reduced but not solved.

References:

Randall, R. P. (2002). A Global Compendium of Weeds. R. G. & F.J. Richardson, Melbourne.
Royal Horticultural Society (1992). Dictionary of Gardening. The Macmillan Press Limited, London.
Blood, K. (2001). Environmental Weeds. A Field Guide for S E Australia, C. H. Jerram & Associates-Science Publishers, Mt Waverley Victoria.
Berry, S and Mulvaney, M. (1995). An Environmental Weed Survey of the Australian Capital Territory. Report prepared for the Conservation Council of the South-east Region and Canberra, Conservation Council of the South-east Region and Canberra, Canberra.