Black locust, Robinia pseudoacacia, Julian, California

In California black locusts are known as a trademark of the Gold Country.  A local San Diego paper announces the “brightening” every spring when the locusts bloom in Julian, a town that prospered after gold was struck in 1870.

When I visited in mid-May, their white blossoms were stunning—occasional bursts of whiteness along the state park road leading to Julian, where the trees lined the streets. In front of one historical building, I found both tall black locust and tree of heaven embracing the small structure.

Black locusts are from two areas in the eastern United States but considered invasive in areas of the country outside of their range. Their gorgeous white flowers have attracted horticulturalists throughout the world. As nitrogen fixers, black locusts add this nutrient to the soil, changing local ecologies. On the other hand, wherever they go, numerous local insects, birds and animals have found them delectable. Their spread raises the question as to how we distinguish between the on-going processes of ecological change and disruptive transformations.