Tragopogon dubius subsp. major

Giant salsify is a stately biennial to short-lived perennial with large, showy yellow flowers that close by midday and produce striking dandelion-like seed heads. It is easy to grow in average, well-drained soil with moderate watering and tolerates partial shade, though it blooms most freely in full sun. Allow seed heads to mature if you want it to naturalize, but be aware it can self-seed prolifically in open ground.