White poplar can grow to 50 feet (15.3 meters) tall and has white-grayish bark. Young twigs and terminal buds are woolly. The leaves are white and woolly on the underside. Leaves on larger shoots tend to be palmately 3-7 lobed and, on shorter shoots, tend to be ovoid or irregularly dentate. White poplar is dioecious, that is, staminate and pistillate flowers occur on different trees. The seeds produced are minute and have silky hairs. No female trees are known to occur in Illinois. All reproduction occurs by root sprouts.
White poplar is native to Europe and Asia. It was introduced in the United States as a shade and ornamental tree, but is rarely used today for these purposes. It frequently escapes cultivation. It is found throughout Illinois and threatens some natural areas. White poplar should be accurately identified before attempting any control measures. If identification of the species is in doubt, the plant's identity should be confirmed by a knowledgeable individual and/or by consulting appropriate books.
White poplar grows in open sunny habitats. It will grow in most soil types and under varied conditions.
In Illinois, white poplar appears to reproduce primarily by vegetative means. Suckers arise from adventitious buds produced on the extensive lateral root system. Profuse suckers from the "mother" plant will form large vegetative colonies. The vegetative colonies (clones) form dense groves that are the primary threat this species poses to natural areas. The dense groves shade out native vegetation. Suckering will occur naturally but also can be enhanced by disturbance to the plant and/or its suckers. Top removal and fires can stimulate suckering.
A single white poplar tree can produce thousands of seeds. The seeds are wind- dispersed and can travel over long distances. However, spread and establishment of this species by seed does not seem to be a problem in Illinois, as most colonies can be traced back to a planted tree.
Effects Upon Natural Areas
White poplar is an aggressive exotic tree species that can take over portions of natural areas, especially prairie communities, shading out native vegetation. It easily escapes cultivation and, if left unchecked, it can form dense groves that are hard to eradicate. White poplar is an aggressive exotic tree species that can take over portions of natural areas, especially prairie communities, shading out native vegetation. It easily escapes cultivation and, if left unchecked, it can form dense groves that are hard to eradicate.