[Wikipedia] Butterfly Threat Via Hybridization: This lupine may represent a significant threat to the survival of the endangered Karner blue butterfly, due to its ease of hybridization with the Karner's food plant, Lupinus perennis, the wild perennial lupine.Some sources argue that commercial lupine seeds are already questionable for the Karner due to hybridization. Additionally, incompatible lupines continue to be introduced by humans into places where the Karner lives or once lived. (link added by Mary Ann Machi)