Cerastium arvense
Whilst botanizing the southern Oregon Mountains the last few springs, I'd run across this plant a few times and thought to myself it's kind of strange it doesn't show up in more rock gardens. Especially here in the drought prone Western US.
It's tidy enough for the rock garden and if you have ever seen it on the dry mountain slopes of the Kalmiopsis where these genetics hail from you know how tough of a plant this is. Great for attracting pollinators to your garden which we all should be doing!
This species typically thrives in a variety of habitats, including fields, grasslands, disturbed areas, and open woodlands. It prefers well-drained soils and can often be found in sunny to partially shaded locations. Cerastium arvense is known for its low-growing, spreading habit and small white flowers that bloom in spring and early summer.