Introduction:
False acacia (Robinia pseudoacacia)
Robinia pseudoacacia is a leguminous deciduous tree native to the southeastern United States that has been widely introduced to other parts of North America. It is commonly found in disturbed areas such as old fields, degraded woods, forest edges, and roadsides, but it poses the greatest threat to dry and sand prairies and oak savannas. R. pseudoacacia has been planted on reclaimed land to control erosion and has been used for ornamental purposes. It reproduces vigorously by root suckering and stump sprouting to form groves of trees interconnected by a common root system.
Description:
R. pseudoacacia is described as a leguminous deciduous tree that grows from 30 to 80 feet tall. Young saplings have smooth, green bark; older trees have deep, furrowed, shaggy, dark bark with flat-topped ridges. Leaves are alternate and pinnately compound with 7 to 21 leaflets. Leaflets are thin, elliptical, dark green above, and pale beneath. Flowers are pea-like, fragrant, white to yellow, and born in large, drooping racemes. Seed pods are shiny, smooth, narrow, flat, 5cms to 10cms long, and contain 4 to 8 seeds. Smaller branches are armed with a pair of setaceous stipules, or stipular spines, that occur at the base of each petiole. These stipular spines are very pronounced on resprouts, and make working among these plants somewhat hazardous.
Occurs in:
Agricultural areas, natural forests, planted forests, range/grasslands, ruderal/disturbed.
Habitat description:
False acacia (Robinia pseudoacacia) Distribution in North America shown in green.
R. pseudoacacia is an early successional plant, preferring full sun, well drained soils, and little competition. It invades dry and sand prairies, oak savannas, and upland forest edges. R. pseudoacacia is commonly found in disturbed areas such as old fields, degraded woods, and roadsides.
General impacts:
Once introduced, R. pseudoacacia expands readily into areas where their shade reduces competition from other (sun-loving) plants. Dense clones of R. pseudoacacia create shaded islands with little ground vegetation. Lack of ground fuel limits the use of fire in natural disturbance regimes. The large, fragrant blossoms of R. pseudoacacia compete with native plants for pollinating bees.
Geographical range:
Native range: R. pseudoacacia is reported to be native to the southeastern United States (lower slopes of the Appalachian Mountains with separate outliers north along the slopes and forest edges of southern Illinois, Indiana, and Missouri).
Known introduced range:Outside of its native range, R. pseudoacacia has become naturalized throughout the United States. It has also been reported in a few Canadian provinces (Converse, 1984). It has been reported as invasive in Cyprus,
Close up of the False acacia (Robinia pseudoacacia)
Korea and Italy.
Introduction pathways to new locations:
For ornamental purposes: R. pseudoacacia has been used for ornamental purposes.
Landscape/fauna “improvement”: R. pseudoacacia is planted on reclaimed land and to control erosion.
Management:
Physical: Cutting R. pseudoacacia stimulates sprouting and clonal spread. For this reason, some recommend against simply cutting the stems. Mowing and burning temporarily control spreading, but mowing seems to promote seed germination, and burning stimulates sprouting. Girdling is ineffective because it kills the stem but does not prevent sucker formation. Annual haying may be adequate to control first year seedlings and prevent spreading in prairie communities. Bulldozing may be an option on disturbed lands.
Sourced From:
