北青龙衣是野生山核桃未成熟的外果皮，是我国传统的民间用药，在《开宝本草》及《本草纲目》中均有记载。
Bei Qinglongyi , the immature wild pecan epicarp , is a traditional kind of Chinese folk medicine , adopted in the record of " Kai Bao Ben Cao " and " Ben Cao Gang Mu " .
开宝本草