I'm piping in although admittedly, I didn't look at all of the links above here. I think it looks like Gomphrena serrata. I see you didn't notice any yellow centers in your flowers but I can see yellow in some of your first photos -This one and the one and the one before and after it.
and it looks just like this one -
http://regionalconservation.or...
http://www.discoverlife.org/mp...
http://www.wildflower.org/gall...
http://plants.usda.gov/core/pr...
**Also meant to mention that a distinct feature of G. serrata is the acute leaves that are present in your plant. This is noted when comparing to G. celosioides, which has nearly obtuse leaves -- according to this site:
https://sites.google.com/site/...
Maybe I'm reading that wrong and you might look at G. celesioides, since you said your plant looks shorter??
