Quick answer: 4 monarch host plants are native to California, 2 with a live listing as of 24 Oct 2026.
4 species
- Narrowleaf milkweed Asclepias fascicularis · 6 states
- Rush milkweed Asclepias subulata · 3 states
- Showy milkweed Asclepias speciosa · 17 states
- Woollypod milkweed Asclepias eriocarpa · 1 states