Tested my theory over the past couple of days and came to this conclusion. Certain realms will always drop rare reagents. I've been farming black pearls and blood moss for the past couple of days. I switch realms to make it easier to farm these things and when i switch to FALMEA realm, i will always get a rare drop of blood moss or a black pearl when picking up red mandrake or black lotus.
So when farming rare reagents, pay attention to what realm you are in when you get that special rare reagent you've been looking for.
question? are you sure your not just LUCKY i have gone in there with a friend and been on the same realm and never got any of those things from that. plz tell me if you just use a plan or if your on at a certain time i need some of those things for my crafting.
If others are farming the same reagents you are, it will take time for all the realms to regenerate the reagents. I go thru all the realms twice before I return to the realms where i know the rare reagents are.
I use FALMEA realm alot when i farm rare reagents and so that being said if you went to FALMEA realm right after i was there, you wouldn't get a rare reagent. Make sense?