Crocosmia aka Montbretia. It is invasive in certain climates so check before you introduce it to your garden and be prepared to watch it carefully. It has taken over large tracts of land in the coastal UK.

Here is a link that might be useful: Crocosmia

In California too. I had to dig up a whole planting bed and strain all the soil through 1/2 inch hardware cloth to get the little root nodules out of the soil before I could replant the bed. Even that did not get them all. Al

More like 'eternal' than 'perennial' when they're happy. They spread by seed or sharply-pointed runners which will easily go through the bulbs of other more-preferred species. And their older bulbs can go down 12" or more, like a string of beads.

Do brilliantly in a sandy/silty soil. Don't mind shade but you'll get more leaves than flowers.

Calistoga is not kidding. They're delightful - in someone else's garden.