During my visit to Couchville Cedar Glades I was looking for a very rare little mustard with white flowers. Then there were these. Can't be the one, they have five petals. So what are they? The quickest way to solve puzzles is to look at the answer. One website says Arenaria patula grows in that preserve. So, easy solution. Until today! Looking this up in FNA to see what they have to say, and they say this is Minuartia. OK, Flora of North America knows what it's talking about. Minuartia it is. Oops! Then if you look at Wiki, you find Mononeuria patula, the newest moniker. Will it stick? Anyway, these are a minimalist delight. The quarter-inch flowers are by far the most noticeable feature. The filiform stems get only a few inches long, with tiny linear leaves. Perfect for growing on wet rocks with minimal nutrients. Limestone barren stitchwort (yes, common names are also flexible) grows in AL, GA, IL, IN, KS, KY, LA, MN, MO, MS, OH, OK, PA, TN, TX, va, and WI. Couchville Cedar Glades, Davidson Co TN, 4/19/22.