MUGWORT

When my Auntie May was alive, she'd fry 'ngai' (Artemisia vulgaris) with eggs and ginger for me whenever I had stomach pains.  According to her, this herb would help to get rid of the wind from my body.  
The lady at the market whom I bought the Ngai from told me that ladies in confinement would boil the Ngai and bathe with the water to get rid of wind.  She also mentioned that it is best to use the old herbs instead of the young ones.
In the western world, Ngai is known as mugwort and it is also widely used as a herb there.  It can be dried for either medicinal, metaphysical, culinary or ornamental purposes.  The westerners also use Mugwort as a Warding herb to repel/banish negative energies, entities/spirits, wild beasts, weariness.  They also make herbal pillows from mugwort to be used as Dream Pillows for those who suffer from insomnia.  Hmm ... perhaps, I'd recommend it to my friends who have trouble sleeping.  
The Chinese tie the mugwort and hang on doors on Double Five day to ward of diseases and negativity.  This belief is also shared by the westerners.  They make swags or wreaths from dry or fresh mugwort branches to place over doors for protection against negative energies. Many believe it will also ward off negative entities.
Reference: http://www.altnature.com/thegarden/Mugwort.html