I just submitted this to the database under Bladder campion and that is wrong it is harry and should not be;
this is either white cockle (Lychnis alba ) or night flowering catchfly (Silene noctiflora)
I assumed Cinda had both of the plants she mentioned and knew it would be one of those. I didn't check the correctness of the name though as it appeared on sites which were educational, but it was going through my mind how much like Silene it was! On ITIS Lychnis alba is a synonym of Silene latifolia.
On the Plant List "Lychnis alba Mill.is a synonym of Silene latifolia subsp. alba" so Silene latifolia subsp. alba would appear to be the correct name. Good job you checked it out Myriam.
Thanks for everyone who helped in identifying this tricky one
also thanks to Myrian for putting it in it's proper place
Evening Lychnis (Silene latifolia subsp. alba)
Name: Maridell Sioux City IA (Zone 4b) enjoy the moment
Starry Campion. I uploaded two purple photos there that belong elsewhere. The photo with the unopened white flower is correct. and http://garden.org/pics/2013-07...
You might add them to the database , if you have not already done so
Oh, and a caption of'' wild collected seed from Japan''would be excellent information.