The US has very strict import laws on seeds, so I don't think it would be easy to bring in plants. The cost of importing even a single plant would require Phytosanitary certification from the supplier, I have bought Crinum from Thailand on ebay from a seller who includes the cost in the price which makes them quite expensive even for Thailand, government certification was on the packet and the 'in growth' Crinums were OK but had been dipped in something and were partly dried up, a cut back stem with no roots. Seeds are allowed from anywhere in the world here but not in the US. A plant would likely have to be sent bare root and certified disease free from a government department in Spain, then put into quarantine once it reached the US and checked after a certain length of time. The plant would be hugely expensive and probably dead.
https://www.aphis.usda.gov/aph...
https://www.cbp.gov/travel/cle...
