Gardeners love to travel and invariably stumble across seeds of unique varieties when visiting other countries. Until recently you've needed a phytosanitary certificate to import seeds into the United States. However, the rules have now changed.
The USDA has instituted new procedures for importing "small lots" of seeds. Small lots are defined as less than 50 seeds each of up to 50 varieties. There's no charge for importing these seeds. All you need to do is fill out the online permit that is valid for three years. The seed needs to be professionally collected with the appropriate information on the packet, such as the collector/shipper's name, the country of origin, and the scientific name (at least the genus).
For more information on how to import small quantities of seed into the U.S., go to: Animal and Plant Health Inspection Service.