http://www.rm3.us/marijuana-as-medicine/the-genetics-of-marijuana/
"Indica and Sativa
There is an enormous amount of contradictory and confusing information about what “indica” and “sativa” types are and what medical properties correspond to these categories. The confusion is not just among the marijuana community; the scientific community can’t
agree, either. Various researchers say cannabis is one, two, or three different species; some divide cannabis into two species, indica and sativa, but then put all drug types – including those we think of as ‘indica’ and ‘sativa’ – into the indica category.
What little agreement there is: some marijuana strains are tall and skinny, with narrow, light green leaves. These are generally assigned by the medical marijuana community to the “sativa” category, and appear to have been bred from the hemp brought to Europe centuries ago from Africa. Other marijuana strains are bushier, with
wider, dark green leaves. These are assigned to the “indica” category and seem to have originated in India and the middle east. Indicas generally are grown indoors, have higher yields than sativas and are usually easier to grow.
Sativa drug strains appear to be a very highly bred subgroup of cannabis plants; they have been selected for generations for only the strongest versions of the THC gene, and the CBD gene has been virtually eliminated. They are the purebreds of the marijuana world; the strains have identifiable characteristics, and if you cross two plants of the same strain, the seeds will run relatively true to the parent.
Indica drug strains, by contrast, seem to have been less highly inbred; there is more genetic variation within and between strains, and the CBD gene is still present in many strains. Seeds are less likely to run true to the parents, and the results of crossbreeding are less certain (and more potentially interesting) than crosses between sativa strains. High levels of THCV are also more common among indica strains.
Finally, there are some strains reported in the literature with very high levels of THCV, CBDV or CBG, with correspondingly lower levels of THC and CBD; we have yet to encounter any of these varieties in our testing."
THANKS to IAN at RM3 for putting this down for us, YOU ARE THE MAN!!!
BOO YAH BITCHES
YALL ARE WELCOME