Gum plant (Grindelia hirsutula). (Sort of, mostly) evergreen perennial.
These plants start blooming when other natives are winding down. They bloom a long time with no supplemental water, grow in clay and might even reseed if they’re happy. They get about two feet tall in our garden, if they don’t flop over.
We tried the coastal variety – it looks almost identical to these plants – but it died out.
If you’re in an area with the right insects, this plant should attract them. We get an occasional native bee, but the flowers are not exactly butterfly magnets here. Your results may vary (we’re in a bad place for butterflies, surrounded by suburban wasteland).