This understated little plant, polygala alba, blends in with the grasses and can be difficult to spot.  I found a few clusters this morning in some open, sparse areas alongside a road. Don’t confuse it with its relative, seneca snakeroot (polygala senega). For a year or so, I had seneca snakeroot identified as white milkwort, until I finally decided both couldn’t be milkwort and needed to just figure it out. Thanks to the book Plants of the Black Hills and Bear Lodge Mountains, the mystery was solved.