A heirloom refers to a local variety of cannabis that was taken from its native land and propagated in another geographic location while maintaining its original genetics. This means that the strain is pure, having never been crossed and always grown in its natural environment. The landrace strains are commonly named after their native regions (e.g. Afghani, Thai, Colombian, Hawaiian). The traces of these native strains are sometimes detectable in the names of its crossbred progeny.