Washington planted 507 Norway maples in 1920 to honor WWI soldiers; the trees later spread into nearby Rock Creek Park as an invasive species
In 1920, D.C. began planting 507 Norway maples on 16th Street to honor its WWI dead. Today, the species is an invasive threat in nearby Rock Creek Park.
We haven't written up this one. Hindustan Times - World News has the full story — the link below goes straight to it.