This question is prompted by a word used in botanical nomenclature: *coggygria*.  

Liddell and Scott show κοκκυγρεα and κοκκυγρια, words used for the tree in question. Is there any evidence that the word κογγυγρια might have existed? 
Also, were there such a word as κογγυγρια, in pronunciation would the first γ be treated as a nasal γ (and thus romanized as *congygria*)?