紫菀（学名：Aster tataricus），又名青菀、紫倩、青牛舌头花（河北土名）、山白菜、驴夹板菜、驴耳朵菜、还魂草、返魂草、小辫，是菊科紫菀属植物。

多年生草本，株高可达1.8米；须根多数簇生；长椭圆形基生叶丛出形大，秋季开花时脱落，茎生叶较狭小互生，上部叶线形；头状花序密集生于茎顶，边缘舌状花篮为淡紫色，中央管状花为黄色单瓣，花期7－9月，果期9－10月，花色秀丽雅致。

Aster tataricus is a member of the Aster genus of flowering plants.

It is one of the 50 fundamental herbs of Traditional Chinese medicine, where it has the name zǐwǎn (Chinese:紫菀). It has an antibacterial action, inhibiting the growth of Staphylococcus aureus, E. coli, Bacillus dysenteriae, B. typhi, Pseudomonas and Vibrio proteus.