Lysimachia paridiformis var. stenophylla

Evergreen clumping perennial with whorls of long glossy emerald foliage topped each summer with clusters of warm yellow flowers nestled in the center. It is reminiscent of a hellebore, just if their foliage could be held up and stay glossy through summer. It's an east Asian plant most commonly found in riparian areas. 

Best grown in light or part shade with rich, well-draining soil. Full sun is just fine in areas with more temperate summers. If you expect winter temperatures on the low end of its temperature range, expect some frost damage ~ purpling-blackening foliage like most "evergreen" perennials. Leave affected foliage up through the winter to protect the crown. 

Spreading perennial 1 ft T x 1-2 ft W, clumping

Minimum temperature: 0° F 

This is a non-invasive clumping perennial not to be confused with its ill-behaved cousins