"Popular lore assigns different characteristics to marijuana plants. For example, Indica-type plants are believed to produce relaxing and sedative effects as opposed to more stimulating Sativa-type plants. The researchers found only a moderate correlation between the ancestry of marijuana strains reported by breeders and the ancestry inferred from their DNA. For example, a sample of Jamaican Lambs Bread, which is classified as C. sativa, was almost identical at a genetic level to a C. indica strain from Afghanistan."
https://news.ubc.ca/2015/08/26/botanists-conduct-first-large-scale-genetic-study-of-marijuana-hemp/
https://news.ubc.ca/2015/08/26/botanists-conduct-first-large-scale-genetic-study-of-marijuana-hemp/