Tel: 1 202 720-5601
Fax: 1 202 690-0472
Telex: 7402320 (PHAPUC)
Inquiries regarding United States Territories, including AMERICAN SAMOA, AMERICAN VIRGIN ISLANDS, GUAM, PUERTO RICO, and also the State of Hawaii may also be made to this address.
Fruits, Vegetables, and Plants:
Plant Protection and Quarantine
P.O. Box 96464
Washington, DC 20090-6464
Attn.: Port Operations.
To bring back endangered plant species, you will also need permits from the country of origin as well as the U.S. Department of the Interior's Fish and Wildlife Service."
U.S. Customs Web site
Export Certification Unit, Port Operations
4700 River Road, Unit 139
Riverdale, MD 20737-1228
Telephone (301) 734-8537
Telefax (301) 734-5786
Searchable Code of Federal Regulations from the US Congress:
Laws pertaining to the Importation of Plant Materials into the United States
(hint) use search words such as:
"phytosanitation certificate", "plant quarantine", "inspection plant importation".
for an example of what laws you can find, try this link: