Well, we know we're talking about Red Sandalwood and Padauk (the "Blood Rosewoods") right now, CanonicalKnight.
Both are endangered, but I wonder how this might possibly be barrier; as I mentioned earlier, by logicale, I would think that helping an endangered seed propogate would encourage importation of seeds from foreign lands. (Other issues as foreign disease aside) But of course, there's a whole lot more that I need to learn, and logicales don't always rightfully determine things.
Thanks for the info. I should look this stuff up.
I don't know about Canada, but for the US, short answer: it depends on what plant, whether it's listed as "Endangered" or "Threatened", how many fees you're willing to pay and how many application forms you're willing to fill out. Long answer: start here - www.aphis.usda.gov and work your way through.
For those wanting to "grow their own", it looks like planting to earliest profitable harvest is 30 years.
ETA: Another site is claiming they can get a profitable return in 13 years. Either way, patience will be a virtue.