Although there are around 450 different species of Cannabis seeds, only around two hundred of them could rank among the good species and only around fifty will come in the grade of pure species. The semillas de cáñamo can only be said to be of very high quality pure species if they can be graded as Sativa or Indica. There are also a number of hybrid species.

Most of the hybrid species of semi di canapa do not find their way to the market of cannabis seeds. They are neither in the group of best species nor they are uniform since their breeds vary to a very great extent. The Pure Cannabis Sativa and Indica are the two species that are considered to be pure. Sometimes a hybrid brand is also created by combination of these two species.

There is however, another pure species of sementes de marijuana plants named Ruderalis. This plant is considered to be a problematic one in the cannabis seeds market. Since it flowers basing on the age, it is not favored by most of the growers. Growers cannot make Ruderalis flower though they try very hard since it is dependent on the season and age.

Only extreme cold conditions as prevalent in Alaska, East Europe and Russia are favorable to growth of Ruderalis, the problematic graine de cannabis. Moreover, the plant has the tendency to auto flower and it is extremely difficult to control the growth in such case. The photoperiod that works in case of Indica and Sativa nicely does not work at all in case of Ruderalis.