"Heroin is an opiate drug that is synthesized from morphine, a naturally occurring substance extracted from the seed pod of the Asian opium poppy plant. Heroin usually appears as a white or brown powder or as a black sticky substance, known as 'black tar heroin.'"
Source
National Institute on Drug Abuse, DrugFacts: Heroin (Rockville, MD: US Department of Health and Human Services, Revised March 2010), last accessed Jan. 12, 2013.
