I was just in the donation corner and noticed that there were a lot of flowers starting with survival, but with no explanation given in the description. What's the lore behind this?

those are flowers associated with the survival holiday, and can be laid at the survivor memorial in centropolis. there is a tiered achievement for doing this that goes up to 1500 flowers.

Those flowers are from the Survival event! You can lay the flowers down at the Survivor Memorial.

Here's info on Survival too!

and thank you!