ivy = artist tag?

I noticed that the tag ivy is assumed to be an artist tag, but looking through some pictures it seems like none of them are by an artist named ivy but rather tagged for the plant. There is also no wiki for info on who this assumed artist is. Could the tag be changed from an artist tag to just a normal tag for the plant?

Unless all Ivy did was collaborations, running searches like ivy arttags:1 -artist_request status:any should turn up pictures by this person, but I'm not finding any. I have a feeling it's something like "there was an artist named Ivy, then they were renamed, but the old tag stayed an artist tag."

EDIT: According to the URL automatically preserved in the uncreated artist page, the tag was created for the artist who did this picture. This artist already has a different name, and the Pixiv commentary says nothing about this being a collaboration.

I switched it to general.