Found growing in backyard in Charleston, SC- close to Eliott’s Cut. Part shade. Plant is maybe a foot tall?
(Also there are some morning glory leaves in photo.)
Hi Virginia, your plant is a wild poinsettia – Euphorbia heterophylla – also known as Poinsettia heterophylla. It is an interesting wildflower. For some reason, the USDA does not show its occurrence in SC, but it is obviously there.
You can find out more about it at: http://plants.usda.gov/java/profile?symbol=Euhe4