Weeping Willow

The weeping willow (Salix babylonica) is an iconic tree native to China. Today, weeping willows and their hybrids are invasive to the Americas, displacing native willow species like the Arroyo willow (Salix lapiolepsis).

If they are both willows, what is the difference? Native species co-evolve and develop complex, symbiotic relationships that stabilize the ecosystem. In this case, the Arroyo willow hosts native pollinators, and its roots provide structure to riverbanks. The invasive weeping willow does not have the same host relationship with native pollinators. In fact, it is a famously difficult ornamental tree because it is prone to diseases and pests, so it often becomes a falling hazard.