All you need to know about seeds. Maybe not all!
http://www.seedselect.com/
D. Seed Legalities
Cannabis seeds contain absolutely NO cannabinoids (THC) and thus are
legal (or at least tolerated) in many countries throughout the world. But in
the United States, cannabis seeds are illegal to possess/import/export.
However, seeds *may* be legal if traded within a state such as California
if intended for personal medical use. In reality, the risks involved with
purchasing/trading seeds is quite small to the buyer. Often the worst that
happens is that the seeds are intercepted and the buyer receives a letter
from customs explaining that illegal contraband was found in mail addressed
to them and that they may contest it (which one should NEVER do). Always
have seeds sent regular first class mail to minimize legal risks.