Under section 412(a) of the Plant Protection Act, the Secretary of Agriculture may prohibit or restrict the importation and entry of any plant or plant product if the Secretary determines that the prohibition or restriction is necessary to prevent the introduction into the United States or the dissemination within the United States of a plant pest or noxious weed.

The Secretary has determined that it is necessary to designate the importation of certain taxa of plants for planting as not authorized pending pest risk analysis, as provided in § 319.37-4. The Secretary has determined that it is necessary to restrict the importation into the United States of all other plants for planting and to impose additional restrictions on the importation of specific types of plants for planting, in accordance with this subpart and as described in the Plants for Planting Manual.

The importation of plants that are imported for processing or consumption, as determined by an inspector based on documentation accompanying the articles, is not subject to this subpart but may be subject to restrictions elsewhere in this part.

The importation of taxa of plants for planting that are listed in parts 360 and 361 of this chapter is subject to the restrictions in those parts.

The Plant Protection and Quarantine Programs also enforces regulations promulgated under the Endangered Species Act of 1973 (16 U.S.C. 1531-1544) which contain additional prohibitions and restrictions on importation into the United States of plants for planting subject to this subpart (see 50 CFR parts 17 and 23).

Within the Plants for Planting Manual, one or more common names of plants for planting may be given in parentheses after most scientific names (when common names are known) for the purpose of helping to identify the plants for planting represented by such scientific names; however, unless otherwise specified, a reference to a scientific name includes all plants for planting within the taxon represented by the scientific name regardless of whether the common name or names are as comprehensive in scope as the scientific name. When restrictions apply to the importation of a taxon of plants for planting for which there are taxonomic synonyms, those restrictions apply to the importation of all the synonyms of that taxon as well.