A farmer walks past a terrace of codonopsis pilosula, a traditional Chinese medicine also known as dang shen, in Min county, Gansu province May 31, 2011. Rows of white plastic shields have been installed to protect the roots of the dang shen to keep it warm and moist. Commonly used as a cheaper substitute for ginseng, the herb is believed to lower blood pressure, boost one's immune system and improve appetite. REUTERS/Stringer (CHINA - Tags: AGRICULTURE SOCIETY HEALTH IMAGES OF THE DAY) FOR BEST QUALITY IMAGE: ALSO SEE GF2E94R0O7V01
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