Nuttall's Evening Primrose (Oenothera nuttallii): white Minnesota wildflowers

Nuttall's Evening Primrose

Plant Info
Also known as:	White-stemmed Evening Primrose
Scientific name:	Oenothera nuttallii
Family:	Evening Primrose (Onagraceae)
Life cycle:	perennial
Origin:	native
Habitat:	sun; dry; sandy soil, prairies
Bloom season:	summer
Plant height:	1 to 3 feet
USDA PLANTS database:	Minnesota county distribution map
Spotted in Ramsey County at:	Long Lake Regional Park

Pick an image for a larger view. Most image enlargements are 50-100KB, though some may be larger. See the glossary for icon descriptions.

Flower:: Flowers are 1 to 2 inches across, 4 white notched petals with a spot of pale yellow at the base of each petal. There are several long yellow stamen. The flower stalk is pinkish. One plant can have several flowers, with 1 to a few at the end of branching stems. The flowers open in the evening and close up in the morning.
Leaves:: Leaves are very narrow with a pointed tip and no leaf stem, alternately attached. The leaves along the main stem are up to 3 inches long and ¼ inch wide with tiny widely-spaced teeth; they are rather shorter on the branches and teeth aren't visible. The stem is smooth and nearly white.
Notes:: The flower photos posted here were taken early in the morning. They were starting to close before 9am and were completely closed well before noon. The stems of Nuttall's Evening Primrose are said to be covered in a peeling white bark, though I did not notice this myself. The stems are nearly white, though.

Photos taken at Long Lake Regional Park, New Brighton, MN July 2008

Have you seen this plant in Ramsey County, or have any other comments about it?