Chaenactis douglasii var. alpina, which was, unfortunately, very short-lived in my garden!
Here it is in nature:
It was short-lived in my garden too. Intermountain Flora considers it a distinct species, "a true, tap-rooted perennial". Perennial in the sense that had it lived, it would have come back the next year.
extreme western edge of Denver, Colorado; elevation 1705.6 meters, average annual precipitation 30cm; refuses to look at thermometer if it threatens to go below -17C
The first step towards proving it a perennial would have been to at least get it through the summer... sigh.
Calgary, Alberta, Canada - Zone 3
-30 C to +30 C (rarely!); elevation ~1130m; annual precipitation ~40 cm
Interestingly, IMF says that C. douglasii is a biennial or short-lived perennial, but it seems to be a tall thing.
(I changed my user ID because I got tired of looking at my name ..)