We made a business trip to Amsterdam a few months ago. As we were leaving, we stopped by the flower market. There were loads of tulip bulbs, flowers, wooden tulips, and various other flowers for sale. We were led to believe by the vendors, that the packaged tulip bulbs could be taken back to the U.S. without any problem - so we purchased several.
This is a drill very well rehearsed for the customs folks, apparently. Upon arrival back in the U.S. and in customs, we were asked if we had any ... agricultural items. Upon inspection, we learned the only ones allowed back in the states were the packages with a USDA seal - so... all our purchases went in the trash. Presumably.
Being a little ticked that we had been played, I decided when we returned home to go out and purchase some tulips, and construct a photo shoot. So now we have tulips in the house... all year long.