Strikingly pretty flower arising from a slender stem in one of my hypertufa troughs. Nothing is clicking, although it looks like some kind of rain lily (which I've not successfully grown before). Zephyranthes, habranthus?

That's a Sabatia, possibly Sabatia kennedyana. I'm not familiar enough with them all to rule out other species as possibilities.
They are so sweet and pretty!

Here is a picture of Sabatia dodecandra http://www.wildflower.org/gall...
and Sabatia kennediana http://www.wildflower.org/gall...
Both are beautiful

Wow, that does make some sense - I thought none of my seedlings survived, and had no idea they looked like that. Thanks!

It looks a lot like Sabatia dodecandra. It's not recorded in Pennsylvania, but is found in some surrounding state but rare.

http://www.pbase.com/ngannet/i...