Sorry but that picture is not of Oenothera, it is Gaura tall and skinny and waving in the breeze like all gauras are.
I know that Oenothera and Gaura belong to the same family Onagraceae, but they are not the same species.
Here is a link to that species;
http://wildflower.org/plants/r...
Please check it out.
Thank you
Josephine