The white flower is a native North American Trillium. From this link it says:
Picking Trillium for their flower can seriously injure the plant. The three leaves (more correctly leafy bracts) below the flower are the plant’s only ability to produce food stores and a picked trillium can take many years to recover. For this reason in many areas, e.g. Michigan, New York, Wisconsin, Minnesota, and Washington, it is illegal to pick and/or transplant trilliums from public lands without a permit from the State.