Distinguishing between two types of Asheirah - "Asheirah of Moshe" and an ordinary Asheirah: Succah 31b
Considering a tree an "Asheirah" if one sees that the idolaters guard it and don't eat from it, even if one doesn't actually see them worship it: Eruvin 79b-80a
Considering a tree an "Asheirah" if one hears idolaters say, "This is for the intoxicating drink of the house of Nitzrifi," which they drink on their holidays: Eruvin 80a