So we a have a machlokes Reish Lakish and R. Yochanan on the subject of a Avoda Zarah she'nishtabra mei'ale'ah
Reish Lakish attempts to prove his point for our mishna in meila which states that a "ken...she'be'asheira, yatiz be'koneh". The presumption here being that the nest was created by itself for the branches of the hekdesh or asheira tree, thereby supported reish lakish as it is "Avoda Zarah she'nishtabra mei'ale'ah" and the mishna says "yatiz be'koneh" Reish Lakish rejects the interpretation the branches for the nest came "me'alma" on the basis of the reisha of the mishna which claims by an ilan shel hekdesh, lo ne'henin, etc. and if it came from somewhere else, me'heichi taysi that we can't chop han'oh.
R. Yochanon in his rebutal remarks that l'olom it is refering to eitzim me'alma. Now instead of the expected continuation (at least according to my expectations) of explaining why you can't chop han'oh if it came from somewhere else, he explains that "yatiz" is not refering to the nest, but rather to the ephrochim themselves which are obviously not assur be'hanoh. Tosfos here explains "klomar, masnisin (meiyri be'chol inyan - shita) ve'aphilu ke'd'aissei me'alma, leka le'akshuay midi...de ha'ken va'dai assur be'hanoh..."
Did I miss something? A moment ago we were so sure that if the eiztim were me'almo, there's is no issur ha'noh, now "...ha'ken va'dai assur be'hanoh..."?
Thank you very much for your time, and sorry about the horrible translitirations.
Tosfos in Avodah Zarah (42b) actually learns the way you wanted - that the nest is Mutar.
However, the Tosfos in Me'ilah writes that it is a Gezeirah lest it be confused with the branches that came from the Asheirah itself.