SciencePhoto: HT WorldTree-of-heaven Spread Across US Since 1784 Introduction
The tree-of-heaven, native to central China and Taiwan, was first introduced as an ornamental plant in Pennsylvania in 1784. It now grows from Maine to southern California, including infestations in Virginia's Shenandoah National Park. The species spread through three introductions from China, including one during the California Gold Rush by Chinese immigrants. Its rapid spread has made it a forest problem in the US.
HT World·




