Acorus gramineus 'Ogon' (Slender sweet flag 'Ogon')
Ogon' is a compact, clump-forming, semi evergreen, grass-like perennial with linear, glossy, yellow leaves with green stripes.
Plant in reliably moist, fertile soil in sun. Can be planted in shallow water in baskets. Evergreen in sheltered sites and good for winter structure/colour in your garden.