うらじろはこやなぎであれば
裏白箱柳であれば
urajirohakoyanagideareba

Noun
Da Copula

The "-eba" conditional form ("if/when…") of うらじろはこやなぎ

1. If it were a hidden, white box willow:; If a hidden, white box willow existed:

Ba Conditional
Usually Written in Kana