Asclepias subulata is Hap’s new favorite perennial. These are very cold hardy (down to 20F) and need only a little water through the summer dry season. They’ll get 4 to 5ft. tall and will attract the usual complement of butterflies and bees and even some birds too.
Native to California as well as Arizona and Nevada and down into Baja too. It will get leaves, but they don’t last long.
These are classically inclined to be complementary with a very dry cactus garden, so go ahead and plan it out that way.