During the 1970s and 80s, cannabis connoisseurs traveled the world and began collecting “landrace” strains to cultivate them in their own local gardens. These pure strains of marijuana are also sometimes referred to as “heirloom” strains and were propagated in other environments like California and Europe.
Landrace strains are local varieties of cannabis that have adapted to the environment and geographic location. This accounts for genetic variation between landrace strains, which have been crossbred to produce the cannabis variety we see today. Landrace strains are oftentimes named after their native region and have very stable genetics.
Most marijuana landrace genetics are 100% Sativa or Indica, although there are some exceptions. The range of pure landrace strains often includes in their name their country or region of origin.
Many people such as Arjan Roskam are strain hunters and continue to travel the world to identify, locate and retrieve cannabis landraces that have not yet been studied, in order to give scientists and doctors the possibility to further enhance knowledge of the cannabis plant in the medicinal field. Many previously unknown cannabinoid profiles are contained in cannabis landraces originating from areas where there is no possibility of scientific research.
For a nice overview on cannabis landrace and heirloom strains, check out this article on The Weed Blog.