Are these three different chilis, or just one, or
are there two varieties being described here?

A fresh poblano chili is often called a pasilla.
I'm guessing the right name is poblano.

On the other side, some dried pasilla chili powder that
I buy is labeled "Pasilla (Ancho)". Which is it?
Is it the same, or different as dried chili labeled
"Ancho"?

Finally, the "Pasilla (Ancho)" stuff is not nearly
as dark as packages of chili powder labeled mereley "Pasilla".

I am thankful this confusion has not extended to engulf
Chimayo, or New Mexico chili.

My last batch of chili had all of the above, plus
red Mexican cherry chilis which were very hot, and
which allowed me to use less of the powders than normal --
resulting in a fresher overall chili.

Steve