Thought this was Caladium but must be ...Syngonium?
Finally got around to moving this "mini Caladium" today. It's been here since before me, up against a north-facing wall. This is the 6th summer I've noticed it. Last summer I started digging it but noticed a huge styrofoam block buried there and thought I had dug it all out (and lost interest in moving this plant that day.)
When I dug up this plant today, there were no bulbs, just another little piece of styrofoam between it and the wall and a group of little plants that didn't seem connected to each other. I dug about a half a foot deeper and carefully examined all of the soil from the area, definitely no bulbs.
I put the tiny plants in a pot together but spread out a bit. I don't know what else it could be besides Syngonium? Each had a root system that looked like a spider plant baby after about 6 weeks in water, 4-6 surprisingly fat white roots about 3-4" long with smaller, thin, squiggly roots coming from those.