Reportedly, it is quite difficult to get guaraná (Paulinia cupana) seeds to sprout. They need to be very, very fresh, days old at the most, and must not be allowed to dry out.

Sorry duplicate - didn't think first posting worked. Mod - pls delete.. TY

I have eyeball/toothache plant seeds.. would love to trade for your Firecracker Vine

I don't think that is an oversimplification - I hear that's how some OP varieties have been improved over time. The reverse could easily happen as well by carrying on the characteristics of a weak plant. We save seeds only from varieties and fruits that taste great, selecting from the strongest plants. Our best germinating seeds are from seeds we've saved. We store them in an airtight plastic tub with a desiccant, kept in the fridge. 10-20% humidity and 40F.