Non-native Species Secretariat

Non-native species information portal

False Acacia
Robinia pseudoacacia

Last edited: October 3rd 2019

False Acacia - Robinia pseudoacacia

Expand and collapse the sections below by clicking on the title or + / - icons.

Short description of Robinia pseudoacacia, False Acacia

A spiny tree up to 29 m, with pinnate compound leaves, having 5-11 pairs of leaflets, and pendent racemes of numerous white, pea-like flowers giving rise to 3-10 seeded pods.

Impact summary: Robinia pseudoacacia, False Acacia

Invasive in woodland and scrub in warmer parts of Western Europe, but not yet to the same extent in GB. Can cause damage to buildings in urban situations.

Habitat summary: Robinia pseudoacacia, False Acacia

Woodland and scrub in its native range as well as in southern Europe, less frequent in semi-natural habitats in GB, but colonises brownfield sites and urban waste ground.

Overview table

Environment	Terrestrial
Species status	Non-Native
Native range	Northern America, Alberta, British Columbia, Labrador, Manitoba, New Brunswick, Nova Scotia, Ontario, Saskatchewan, Yukon
Functional type	Land plant
Status in England	Non-Native
Status in Scotland	Non-Native
Status in Wales	Non-Native
Location of first record	v.c.63
Date of first record	1888

Origin

Eastern United States in the Appalachian Mountains from Pennsylvania southwards, with outliers from Kentucky to Georgia.

First Record

Introduced to GB in the 1630s, in the wild by 1888.

Pathway and Method

Planted as an ornamental tree in parks and streets, also in land reclamation schemes on brownfield sites. It is still available from suppliers, especially in the form of decorative cultivars.

Species Status

Widely naturalised and invasive in mainland Europe, especially towards the south, locally persistent by suckering, but also sometimes self-seeding, especially in southern and eastern counties of England. Between 1970 and 1986 it was recorded in 143 10km squares in GB and from 1987 to 1999 from 491 squares.

Dispersal Mechanisms

Spreads by suckering where it has been planted. Produces prolific seed, though self-seeding is less frequently reported than suckering, and mainly in southern GB.

Reproduction

The flowers are bisexual and pollinated by bees. They give rise to pods with 3-10 seeds.

Known Predators/Herbivores

A number of insects feed on False Acacia in its native range, but in GB and mainland Europe it is little affected.

Resistant Stages

The seeds have tough coats and germination rates are low.

Habitat Occupied in GB

Parks, gardens, streets, colliery tips and other sites where former industrial land is being restored. Self-sown on urban waste land and brownfield sites.

Mainly in southern and eastern England on light and calcareous soils, scattered records from elsewhere in GB.

Environmental Impact

Appreciable in central and southern Europe, where it invades semi-natural habitats, less serious at present in GB as it colonises mainly urban and brownfield sites. The presence of nitrogen-fixing root nodules leads to eutrophication of invaded sites.

Health and Social Impact

None known.

Economic Impact

False Acacia has been important in the reclamation of abandoned industrial sites and for soil stabilisation. In France it provides nectar for acacia honey. In urban situations it can damage structures. Where it has invaded vulnerable habitats it is difficult and costly to remove.