Although there are some grammar errors (I'll try to weed those out later if I can), I thoroughly enjoyed this. What piqued my interest the most was the "Dad" note, meaning this definitely could've originated from an actual person at one point who strived to gather info to impress their child before turning supernatural.
I also think this could go a bit further to gain more interest.
Have you thought about adding plants that are considered extinct nowadays and have them date back to the prehistoric era? Along with the notes containing information on them that scientists today don't even have (fictional "facts" of course).
Another idea (involving extinct/fictional plants) is have some that contain healing properties that would baffle scientists. For example: A D-Class personnel, who is suffering from natural conditions similar to eczema, is ordered to come into contact with an unidentified leaf the book is holding. A day or so after, they report that their conditions/symptoms majorly improved far beyond what their prescribed medications ever allowed.
So yeah. Great idea, just could use a bit more interesting info/tests to stretch it out and spice things up. I'll be happy to help you with plenty of other ideas if you'd like. So feel free to message me.
(Edit: I tend to think of ideas randomly and add on. So excuse my constant revisions to posts)
