Blooming from mid-April to early May, cutleaf toothwort (Dentaria laciniata or Cardamine concatenata, Brassicaceae) exhibits the four-petaled flower arrangement typical of members of the mustard family. Its large flowers and relative abundance in eastern woodlands makes it a favorite of insect pollinators. It also seems to attract spiders that feed on the pollinators.
Although predominantly white, I sometimes see them tinged with pink. I suspect this coloration is exhibited near the end of the flowering period, as is often seen with white trilliums.
The most obvious characteristics that sets cutleaf toothwort apart from other woodland mustards are the narrow and coarse-toothed leaves. These leaves are pretty distinct, and make it easy to spot this plant even before they start to flower.