Either after the flower blooms or there is just a leaf, it fans out and has a distinctive shape. Some liken it to Batman with his cape spread out. What do you think?
Here is an interesting specimen. This plant only developed 4 petals.
The sap from this plant is a bright red color. This sap has been used as a dye by Native Americans and early colonists. There is a long history of medicinal uses by Native Americans as well. In the 1990s scientists discovered the alkaloid, sanguinarine within the sap. This substance was widely used in toothpastes and mouthwashes as an anti-plaque substance until some bad side effects were known.
So, as we are a Nature Preserve I don't want to intentionally injure on of our bloodroot plants, so here is a link to a photo of the sap on bugguide.net.
I had help from a couple of great sources for this post:
Spring Wildflowers of the Northeast by Carol Gracie - you can view her blog here
The Book of Forest and Thicket by John Eastman