Rusmore and Butler are part of a group identifying invasive exotic weeds that are cropping up along the parkway. The strangers come from far and wide, usually brightly dressed and exhibiting a charming manner. Then they make themselves so much at home, helping themselves to food and water while producing offspring, that the original occupants are forced to move.
Spanish broom provides interesting color but is threatening native plants along the American River.
These strangers are plants, not people, and usually arrive here for their otherwise commendable attributes of good looks, easy adaptability and fast growth. Examples are the numerous varieties of broom, a flowering shrub that turns places like the Nevada County community of North San Juan into a carpet of gold in spring. It's lovely to behold, but it has overwhelmed virtually every other native shrub. When native plants disappear, so do all of the animal species that depend on them for food and shelter. What's left behind are a small number of aggressive non-native plants.