California Code, Food and Agricultural Code (Formerly Agricultural Code) - FAC § 80152

All native plant species or varieties subject to this division, when not grown in California and imported into this state, shall be declared at a California agricultural inspection station or an office of the department, and proceed to destination under quarantine orders issued by agents of the department employed at the station or office. Any person transporting any plant species or varieties subject to this division from outside the state into California shall have in his or her possession a valid bill of sale for those native plants, and such permits and tags as may be required by the state of origin, and shall produce the bill of sale as well as any permits and tags for inspection by any duly authorized person as described in this division or any peace officer of the state as a requirement for entry into the state of the native plants.