Some time ago the plant on the left was identified for me as claytoniavirginica. Is the one on the right the same flower, even though the colour is dramatically different?
Plenty of flower petal colour variation in members of the Montiaceae, so within the realm of possibility.
I'd check leaves of one on left (as well as floral details) to make sure they were those of Claytonia virginica before using that name as a reference or starting point.