1. (a) Seeds of the plants listed in paragraphs (a)(1) and (a)(2) of this section shall be considered noxious weed seeds.

   1. (1) Seeds with no tolerances applicable to their introduction:

      Acacia nilotica (Linnaeus) Wildenow ex Delile Aeginetia spp. Ageratina adenophora (Sprengel) King & Robinson Ageratina riparia (Regel) R.M. King and H. Robinson Alectra spp. Alternanthera sessilis (L.) R. Brown ex de Candolle Arctotheca calendula (Linnaeus) Levyns Asphodelus fistulosus L. Avena sterilis L. (including Avena ludoviciana Durieu) Azolla pinnata R. Brown Carthamus oxyacantha M. Bieberstein Chrysopogon aciculatus (Retzius) Trinius Commelina benghalensis L. Crupina vulgaris Cassini Cuscuta spp. Digitaria abyssinica (Hochstetter ex A. Richard) Stapf Digitaria velutina (Forsskal) Palisot de Beauvois Drymaria arenariodes Humboldt & Bonpland ex J.A. Schultes Eichhornia azurea (Swartz) Kunth Emex australis Steinheil Emex spinosa (L.) Campdera Euphorbia terracina Linnaeus Galega officinalis L. Heracleum mantegazzianum Sommier & Levier Hydrilla verticillata (Linnaeus f.) Royle Hygrophila polysperma T. Anderson Imperata brasiliensis Trinius Imperata cylindrica (Linnaeus) Palisot de Beauvois Inula britannica Linnaeus Ipomoea aquatica Forsskal Ischaemum rugosum Salisbury Lagarosiphon major (Ridley) Moss Leptochloa chinensis (L.) Nees Limnophila sessiliflora (Vahl) Blume Lycium ferocissimum Miers Lygodium flexuosum (Linnaeus) Swartz (maidenhair creeper) Lygodium microphyllum (Cavanilles) R. Brown (Old World climbing fern) Melaleuca quinquenervia (Cav.) Blake Melastoma malabathricum L. Mikania cordata (Burman f.) B. L. Robinson Mikania micrantha Kunth Mimosa diplotricha C. Wright Mimosa pigra L. var. pigra Monochoria hastata (L.) Solms-Laubach Monochoria vaginalis (Burman f.) C. Presl Moraea collina Thunberg Moraea flaccida (Sweet) Steudel Moraea miniata Andrews Moraea ochroleuca (Salisbury) Drapiez Moraea pallida (Baker) Goldblatt Nassella trichotoma (Nees) Hackel ex Arechavaleta Onopordum acaulon Linnaeus Onopordum illyricum Linnaeus Opuntia aurantiaca Lindley Orobanche spp. Oryza longistaminata A. Chevalier & Roehrich Oryza punctata Kotschy ex Steudel Oryza rufipogon Griffith Ottelia alismoides (L.) Pers. Paspalum scrobiculatum L. Pennisetum clandestinum Hochstetter ex Chiovenda Pennisetum macrourum Trinius Pennisetum pedicellatum Trinius Pennisetum polystachion (L.) Schultes Prosopis alapataco R. A. Philippi Prosopis argentina Burkart Prosopis articulata S. Watson Prosopis burkartii Munoz Prosopis caldenia Burkart Prosopis calingastana Burkart Prosopis campestris Grisebach Prosopis castellanosii Burkart Prosopis denudans Bentham Prosopis elata (Burkart) Burkart Prosopis farcta (Banks & Solander) J.F. Macbride Prosopis ferox Grisebach Prosopis fiebrigii Harms Prosopis hassleri Harms Prosopis humilis Gillies ex Hooker & Arnott Prosopis kuntzei Harms Prosopis pallida (Humboldt & Bonpland ex Willdenow) Kunth Prosopis palmeri S. Watson Prosopis reptans Bentham var. reptans Prosopis rojasiana Burkart Prosopis ruizlealii Burkart Prosopis ruscifolia Grisebach Prosopis sericantha Gillies ex Hooker & Arnott Prosopis strombulifera (Lamarck) Bentham Prosopis torquata (Cavanilles ex Lagasca y Segura) de Candolle Rottboellia cochinchinensis (Lour.) W. Clayon Rubus fruticosus L. (complex) Rubus moluccanus L. Saccharum spontaneum L. Sagittaria sagittifolia L. Salsola vermiculata L. Salvinia auriculata Aublet Salvinia biloba Raddi Salvinia herzogii de la Sota Salvinia molesta D.S. Mitchell Senecio inaequidens DC. Senecio madagascariensis Poir. Setaria pumila (Poir.) Roem. & Schult. subsp. pallidefusca (Schumach.) B.K. Simon Solanum tampicense Dunal (wetland nightshade) Solanum torvum Swartz Solanum viarum Dunal Sparganium erectum L. Spermacoce alata Aublet Striga spp. Tridax procumbens L. Urochloa panicoides Beauvois

   2. (2) Seeds with tolerances applicable to their introduction:

      Acroptilon repens (L.) DC. (=Centaurea repens L.) (=Centaurea picris) Cardaria draba (L.) Desv. Cardaria pubescens (C. A. Mey.) Jarmol. Convolvulus arvensis L. Cirsium arvense (L.) Scop. Elytrigia repens (L.) Desv. (=Agropyron repens (L.) Beauv.) Euphorbia esula L. Sonchus arvensis L. Sorghum halepense (L.) Pers.

2. (b) The tolerance applicable to the prohibition of the noxious weed seeds listed in paragraph (a)(2) of this section shall be two seeds in the minimum amount required to be examined as shown in column 1 of table 1 of § 361.5. If fewer than two seeds are found in an initial examination, the shipment from which the sample was drawn may be entered. If two seeds are found in an initial examination, a second sample must be examined. If two or fewer seeds are found in the second examination, the shipment from which the samples were drawn may be entered. If three or more seeds are found in the second examination, the shipment from which the samples were drawn may not be entered. If three or more seeds are found in an initial examination, the shipment from which the sample was drawn may not be entered.

3. (c) Any seed of any noxious weed that can be determined by visual inspection (including the use of transmitted light or dissection) to be within one of the following categories shall be considered inert matter and not counted as a weed seed:

   1. (1) Damaged seed (other than grasses) with over one half of the embryo missing;

   2. (2) Grass florets and caryopses classed as inert:

      1. (i) Glumes and empty florets of weedy grasses;
      2. (ii) Damaged caryopses, including free caryopses, with over one-half the root-shoot axis missing (the scutellum excluded);
      3. (iii) Immature free caryopses devoid of embryo or endosperm;
      4. (iv) Free caryopses of quackgrass (Elytrigia repens) that are 2 mm or less in length; or
      5. (v) Immature florets of quackgrass (Elytrigia repens) in which the caryopses are less than one-third the length of the palea. The caryopsis is measured from the base of the rachilla.
   3. (3) Seeds of legumes (Fabaceae) with the seed coats entirely removed.
   4. (4) Immature seed units, devoid of both embryo and endosperm, such as occur in (but not limited to) the following plant families: buckwheat (Polygonaceae), morning glory (Convolvulaceae), nightshade (Solanaceae), and sunflower (Asteraceae).
   5. (5) Dodder (Cuscuta spp.) seeds devoid of embryos and seeds that are ashy gray to creamy white in color are inert matter. Dodder seeds should be sectioned when necessary to determine if an embryo is present, as when the seeds have a normal color but are slightly swollen, dimpled, or have minute holes.

[62 FR 48460, Sept. 16, 1997, as amended at 64 FR 12884, Mar. 16, 1999; 65 FR 33743, May 25, 2000; 71 FR 35381, June 20, 2006; 74 FR 53400, Oct. 19, 2009; 75 FR 68956, Nov. 10, 2010]