I'm assuming that this is something that was intentionally planted by a previous property owner. The flowers have four petals, this was the only one that was starting to open. They don't seem to get more than 8 inches tall and don't run.
Wow. The Tortoise Table has it listed as safe. The have a different variety pictured is what threw me off! Now to see what Clunker's opinion of it is.. stay tuned..