Early one recent morning as the sun was rising over Medicine Lake (Siskiyou County CA), a volcanic caldera, I was greeted by the bright yellow flowers of tansyleaf evening primrose (Camissonia tanecetifolia) peeking through the sedges on the shore. This native evening primrose species grows in meadows and open areas, either wet or dry. How beautiful to watch the flowers open in the warmth of the sun.
Found in the western states, tansyleaf evening primrose is also commonly called tansyleaf sun cup. A perennial, this wildflower grows from a taproot and spreads via lateral shoots. The frilly leaves are arranged in a prostrate or flat rosette. Long and narrow, the leaves have deep, slender, irregular lobes and are densely covered with hairs. Long petioles (stems) connect the leaves to the taproot.
The flowers are on erect stems arising from the center of the leaf rosette. The four petals have rounded tips. The sepals are reflexed (bent) back. The stigma (top part of the female reproductive organ) is a round lobe. The rounded petal tips and round stigma are field traits separating tansyleaf evening primrose from other frilly leafed primroses.
I am not aware of any uses for tansyleaf evening primrose other than to raise my spirits and provide a bit of sunny color to the landscape.