Common Evening Primrose
Common Evening Primrose
Oenothera biennis
Evening Primrose Family - Onagraceae
Terminal spike of 4-petalled yellow flowers (opening in evenings and closing by noon) with 8 prominent stamens and a central cross- shaped stigma. Seed pods 4 to 5 times longer than wide.
(Photographed - August)
A generally tall plant with plentiful lance-shaped, alternating leaves (4 to 8 inches long) with wavy to slightly toothed margins.
  Pathology Images Inc. 2000 to 2002