A close up of dried "Bubba Kush" flowers.
Kush refers to a subset of strains of Cannabis indica. The origins of Kush Cannabis are from landrace plants mainly in Afghanistan, Northern Pakistan and North-Western India  with the name coming from the Hindu Kush mountain range. "Hindu Kush" strains of Cannabis were brought to the United States in the mid-to-late 1970s and continue to be available there to the present day.
Kush strains were among those cultivated by the British firm GW Pharmaceuticals for its legally licensed commercial trial of medicinal cannabis.
US Congressman Mark Kirk, then a Republican member of the House of Representatives from Illinois, introduced legislation to increase the penalties for selling kush. The High-Potency Marijuana Sentencing Enhancement Act of 2009 (H.R. 2848) would increase the penalties for the possession with intent to distribute, manufacture, import or export to maximum fines of $1 million for an individual and $5 million for a group, with a maximum sentence of 25 years from the standard sentencing for marijuana which calls for a maximum fine of $250,000 for an individual, $1 million for a group and up to five years in prison. Kirk believes that as kush may sell for up to $560 (USD) per ounce these increases are justified, saying that "if you can make as much money selling pot as cocaine, you should face the same penalties."