(a) Phytosanitary certificates of inspection. Any restricted article offered for importation into the United States must be accompanied by a phytosanitary certificate, unless the article is explicitly exempted from this requirement in the paragraphs below. The phytosanitary certificate must identify the genus of the article it accompanies. When the regulations in this subpart place restrictions on individual species or cultivars within a genus, the phytosanitary certificate must also identify the species or cultivar of the article it accompanies. If the plant is grafted, budded, or otherwise contains interpolated plant parts, the phytosanitary certificate must list the identity of any plant parts (e.g., scion, rootstock, or interstem) that belong to restricted taxa to the lowest regulated taxon, e.g., genus, species, or cultivar. Otherwise, identification of the species is strongly preferred, but not required. Intergeneric and interspecific hybrids must be designated by placing the multiplication sign ``x'' between the names of the parent taxa. If the hybrid is named, the multiplication sign may instead be placed before the name of an intergeneric hybrid or before the epithet in the name of an interspecific hybrid. Phytosanitary certificates are not required to accompany the following restricted articles: