I moved closer, hoping that might help, and here's what happened.
The sun and its reflection from the camera created a green arc in the camera's eye, although not actually on the ground or not that my eyes could see on the ground.
Here the sun transforms an interior scene. One can see from this photo--of objects on a table bathed in oblique sunlight coming in from an unseen window to the right with open blinds--why impressionists, who wanted to paint light, wound up breaking the surface of objects and hence the paint surface. Striated sunlight makes objects a bit jumpy.