Did you know that Japan has a famous set of seven fall flowers? In Japanese it’s 秋の七草 (aki no nana kusa).
Here are the names in Japanese and English オミナエシ (valerian)、ススキ (miscanthus)、ナデシコ (dyanthus)、キキョウ (Chinese bellflower)、フジバカマ (boneset)、クズ (kuzu)、ハギ (bush clover).
The list goes back to the ninth century, and is related to haiku. The Japanese Wikipedia page shows the seven fall flowers at the Ise shrine. They are all hardy plants native to Japan.
I noticed this set because my neighborhood flower shop sold me kikyou recently. My balcony garden also has fujibakama (フジバカマ) and nadeshiko (ナデシコ). I should look for the other four to better connect my small garden with Japanese culture.
BTW, spring has a set of seven edible herbs, which are eaten on the seventh day of the new year.