Common name: Missouri primrose, Missouri evening primrose, evening primrose, Ozark sundrops
Botanical name:Oenothera macrocarpa (formerly O. missouriensis)
Virtues: Larger flowers than many other wildflowers; tolerates drought and poor soil; long bloom period. 2004 Kansas Wildflower of the Year.
Flowers: Bright yellow flowers can be 5 inches across, with 4 petals and a slight fragrance. They usually open in late afternoon and they are pollinated by naight-flying sphinx moths. Blooms from spring through summer.
Foliage: Narrow and dark green.
Habit: Grows 1 foot tall and slightly wider. Its low, sprawling habit and ability to self-seed makes it a good groundcover.
Origin: Limestone glades, roadsides and rocky prairies of southern and central United States.
Cultivation: Needs full sun and well-drained soil, though it will tolerate light shade. Tolerates drought and poor soil. Can spread by self-seeding, although it is not nearly as aggressive as its cousin pink evening primrose (O. speciosa), which many a gardener has regretted planting because it takes over. USDA Zones 3–7.
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Image courtesy of Missouri Botanical Garden PlantFinder