Many readers will likely recognize most of the ones I include on this post. Probably the most recognizable one is the White Trillium, the provincial flower of Ontario.
Another uncommon plant is this next one: American Gromwell.
From even a short distance away, it blends in with the lush vegetation it grows amongst, so it isn't surprising that it can be missed.
At least a few of these will continue to bloom well into June.