The Mission Blue is a blue or lycaenid butterfly subspecies native to the San Francisco Bay Area of the United States. The butterfly has been declared as endangered by the US Federal Government. It is a subspecies of Boisduval’s Blue.
Though it has the word weed in its common name, don't let that scare you away from butterfly weed (Asclepias tuberosa). Sometimes called milkweed, it's as easy to grow as a weed but much prettier, plus hummingbirds and butterflies love them!