Monarch Egg on Black Swallowwort
Black swallowwort is an invasive perennial vine in the milkweed family. Monarchs lay eggs on it, but sadly the caterpillars don't survive to maturity. As an invasive plant, black swallowwort is doubly destructive outcompeting native plants and having a negative impact on monarch populations.
Canton/Milton, MA, 7/5/12