Right is
每 'every', supplying the sound — měi drifting to méi with tone shift. Same phonetic in
莓 berry,
霉 mold,
海 sea (originally měi-shifted),
悔 to regret. The plum's image as the tree that flowers every winter dovetails neatly with
每, giving learners an easy mnemonic: 'the every-winter tree.'