Cannabis Indica, adapted to the harsher climate conditions has shorter flowering conditions, grows bushy, with broader leafs than Sativa. As more abundant in mass it is more convenient for industrial and indoor cultivation.
Cannabis originated in Asia, where it was subject to early domestication by the ancient nomadic tribes. They used it for fiber, but also as food. Opening of trade waterways lead to its spreading into other parts of the world. At the time, it was thought that only one sort of Cannabis exists.
Cannabis I. strains such as Blue Cheese, or Granddaddy Purple will disperse anxiety, deliver calmness and body relaxation. Other, well known I. strains like Banana Kush, Tahoe OG, or Indica Bland produce feeling of serenity, bodily bliss and relaxation, with more accented introspection and self reflection focus.
The difference between Cannabis I. and Sativa plant origin, morphology and general effects are factual, but still they are mainly useful for breeders and farmers. Therefore they should be taken as background information, not a strict distinction. Moreover, most of the plants today are a mixture of the two sorts and it is very difficult to locate pure Indica or Sativa strains.
This is why, above mentioned Sativa vs Indica active/passive, extrovert/introvert – dichotomy should not be taken in absolute terms.
By mixing two main sorts of cannabis numerous hybrid strains have been created. This was done to get more balanced and precise effects of the plants for the consumers, but also to better the farming efficiency.
For this reason, knowing exactly what you want from your weed means a lot, as most of the strains in the market today are hybrids. Many of the commercial hybrids are marked as Indica or Sativa dominated, indicating that they carry the majority characteristics of dominant sort and less of the secondary one.