This is not an answer to your question, but more of a suggestion.
You should check out the UI mod called "Gatherer". It records where you found herbs and lets you show them on your map. There used to be a Windows app to export the data so you could swap it with other people. I found a web site once that had exports for download. Could easily get a huge database going for all herbs.
I'm not sure if the UI creator still has the windows app available though, or if the other sites are still around...