Edin. To find this flower, you must first kill the King of Slimes (and read the scroll that drops from him) then repeat the same with the Eye of Cthulhu and then with the Queen Bee. After reading the scroll that dropped from the Queen Bee, you will find Edin, which drops from bushes in the jungle. In fact, this is how it works with each new plant or berry. Tier means the number of the scroll that needs to be read. All scrolls, as well as which bosses need to be killed to get them, are described in the official Atherius wiki https://coblermod.fandom.com/wiki/Herbalist_Scrolls