'Apple tree' in the Bible

Who is this coming up from the wilderness, leaning on her Beloved? I awakened you under the apple tree; there your mother travailed with you; there she travailed and bore you.

The vine is dried up, and the fig tree droops, the pomegranate and the palm tree, and the apple tree; all the trees of the field are dried up, because joy has dried up from the sons of men.