I prefer the term cannabis user to dope smoker - however I think that this is important news...so here's the article (google news).
AS POLICE and dope smokers know, there are two types of cannabis. Cannabis sativa sativa is mainly used to make hemp, while the indica subspecies is prized for its tetrahydrocannabinol (THC) content, which produces the "high". But now Australian researchers have discovered a third type of cannabis, called rasta.
Simon Gilmore of the Canberra Institute of Technology catagorised 196 sample plants according to the DNA in their mitochondria and chloroplasts. The samples included plants grown for drugs and hemp as well as wild varieties from Europe, Asia, Africa, Mexico and Jamaica.
The results showed three distinct "races" of cannabis. In central Asia the THC-rich indica predominated, while in western Europe sativa was more common. In India, south-east Asia, Africa, Mexico and Jamaica the rasta variant predominated. It looks similar to the sativa subspecies, but generally contains higher levels of THC.
Since the study was of DNA rather than a formal taxonomic study, Cannabis sativa rasta is not yet an official new subspecies: the name was the result of a competition in Gilmore's lab. Their work is expected to appear in the journal Forensic Science International later this year.