As I understand it, the ‘ae’ ending from a taxonomic family is pronounced ‘ah’ or ‘ee’ depending on if it is singular or plural. So I might say the daisy is my favorite Asteraceae (aster-a-cee-ah) -singular- or of all Asteraceae (aster-a-cee-ee) -plural- the daisy is my favorite.
Latin/Greek plays some weird games. Is my understanding correct?
The singular would, strictly speaking, in Latin be Asteracea, which answers your pronunciation question.
Or you could say “my favourite of all the Asteraceae (plural)”
I think that ae is a stand-in for the schwa, ə.
-ae is the first declension plural of feminine nouns ending in -a. Schwa has nothing to do with it.
It depends on what school of Latin pronunciation you subscribe to, but it’s not dependent on whether a word is singular or plural.
The traditional Anglicized pronunciation of Latin renders “ae” as /i/ as in “heed.”
The classical pronunciation of Latin renders “ae” as /ai/ as in “hide.”
And the Italianate pronunciation used in the Catholic Church since the Counter-Reformation, ae is pronounced /e/ as in café.