This is a new-to-me plant, Sand Jointweed (Polygonella articulata). It’s not in any of my field guides, so it took me a while to find out what it is.
To tell the truth, I only discovered its identity by happy accident. I was reading Saratoga woods and waterways and there it was. A plant I have seen for a couple of years and not known what it was.
It does not seem to be a very common plant. Wikipedia has no article on it, and Wikimedia Commons doesn’t seem to have any photos of it either. There is not very much information on it at the Ladybird Johnson Wildflower Center either.
This one was growing between the edge of the woods and the edge of the parking lot at the church. I took a hurried shot of it this morning, but I need to get out there and take a more careful one. Maybe then we can think about Wikipedia and the Commons.