kush genetics originate from the hindu kush mountains and are indica dominant. but this doesnt mean that a strain labeled 'kush' today cannot be a sativa. for one thing, most of these strains are crosses with multiple strains which may be sativas, thus creating a hybrid with some kush genetics. the many different cuts of og kush for example are a very popular hybrid kush but it has very little afghan kush genetics in it lineage and is actually usually very much a sativa dominant hybrid. but ur right a PURE kush by definition should be indica.
another thing to consider are the phenotypes of the plant. you can have 5 seeds of some indica hybrid, but depending on the stability of the genetics, this doesn't mean all 5 of the plants are going to show the same exact phenotypes consistently. there is always a chance a seed that typically yields an indica phenotype may produce a plant that carries a more sativa like phenotype and physical characteristics instead. this however will not effect 100% pure genetics tho...this only occurs in hybrids.
Edited by aes-one, 22 August 2011 - 09:30 AM.