Astilbe is a flower (the final e is not silent, pronounce it like the e in "evil," ah-STILL-bee). The name's derived from stilbos, Greek adjective meaning "glittering" or "gleaming," and a-, a prefix meaning "not." So astilbe is "not gleaming"--"because the individual flowers are small and inconspicuous," says my computer's dictionary.
If I were astilbe, I'd be pissed off that no one bothered to name me after a quality I did have, rather than one I didn't. I mean, it's like calling the poor plant So-so Wort or Flowering Kindasucks.
At one point I had it in mind to compose a sonnet cycle in which astilbe complained about its name and various other things. At the end it would break down in tears and, of course, die (because of the salt water). I will not write this cycle, but I did envision it ending with astilbe's epitaph, and this I have written. Here it is:
In death you will find peace. Be still, astilbe!
Nor fear you won't be loved: for now, you will be.