For both humans and butterflies, Baja passion vine (Passiflora foetida v. longipedunculata) is a tasty plant. The larvae of the Gulf fritillary munch on the foliage, and people enjoy the juicy grape-size fruit. Native to Baja California, it is heat tolerant and sports the sort of intricate (albeit smaller) white-and-purple flowers you expect from a passion vine. This twining vine climbs up to 15 feet in a single growing season. Note to humans: The fruit is ripe when it drops from the vine.
True to its name, the soft leaves of the woolly butterfly bush (Buddleja marrubifolia) are covered with silver fuzz and the plant does attract butterflies. The 5x5-foot evergreen shrub is a workhorse in the garden; it is tolerant of heat, cold, intense sunlight, and drought. Its orange, globe-shape flowers aren't garishly showy, unless you happen to be a pipevine swallowtail butterfly, which visits the woolly butterfly bush frequently for nectar.
A magnet for queen butterflies, the fuzzy lavender flowers of boneset (Conoclinium greggii syn. Eupatorium greggii) create a flutter of activity during the warm months. Cut back this low-growing perennial in late spring and periodically deadhead in summer to keep the flowers and butterflies coming. Provide boneset with moderate irrigation for best summer appearance.