Thermopsis macrophylla, commonly known as Santa Inez Goldenbanner, is a rhizomatous perennial herb endemic to the chaparral and open woodlands of California, particularly in the Santa Ynez mountains of Santa Barbara. It thrives on sandstone-derived soils within these ecosystems, often in association with chamise, Eastwood’s manzanita, and chaparral whitethorn. Santa Inez goldenbanner can reach up to 7 feet in height and 3 feet in width, and is notable for its bright yellow, pea-like flowers that bloom in the spring and early summer, adding a splash of color to the landscape.

The plant’s showy flowers and ability to adapt to dry, rocky soils make it an attractive choice for native plant gardens, xeriscaping, and restoration projects. It is also valued for its role in supporting native pollinators. Santa Inez goldenbanner requires little maintenance once established, but it does need well-drained soils and full sun to partial shade to thrive. While it is adapted to periodic wildfires, which help to scarify its seeds and promote germination, in cultivation, manual scarification can substitute for this natural process.CC BY-SA 4.0