There are many different wildflowers that signal the seasonal transition from summer into fall.
I used to be overcome with the melancholy of fall when I would see the goldenrods (Solidago spp.) start to bloom, thinking “No, it’s too early for the end of the blooming season and the start of winter!” That’s how I used to think of fall. Goldenrods no longer usher in the sadness for me as I have successfully reframed them as a summer wildflower that blooms into fall.