Oenothera macrocarpa subsp. incana
Pewter Moon Evening Primrose. A fine very large flowered form with green to gray leaves and reddish stems. Big rounded golden yellow flowers open at dusk and carry on well into the next day. A good hardy and drought tolerant plant that works it in the rock garden or Garden of Neglect. Worth growing just to watch the Sphinx Moths go delirious in the gloaming. Good drainage.