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

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

Acacia nilotica (Linnaeus) Wildenow ex DelileAeginetia spp.Ageratina adenophora (Sprengel) King & RobinsonAgeratina riparia (Regel) R.M. King and H. RobinsonAlectra spp.Alternanthera sessilis (L.) R. Brown ex de CandolleArctotheca calendula (Linnaeus) LevynsAsphodelus fistulosus L.Avena sterilis L. (including Avena ludoviciana Durieu)Azolla pinnata R. BrownCarthamus oxyacantha M. BiebersteinChrysopogon aciculatus (Retzius) TriniusCommelina benghalensis L.Crupina vulgaris CassiniCuscuta spp.Digitaria abyssinica (Hochstetter ex A. Richard) StapfDigitaria velutina (Forsskal) Palisot de BeauvoisDrymaria arenariodes Humboldt & Bonpland ex J.A. SchultesEichhornia azurea (Swartz) KunthEmex australis SteinheilEmex spinosa (L.) CampderaEuphorbia terracina LinnaeusGalega officinalis L.Heracleum mantegazzianum Sommier & LevierHydrilla verticillata (Linnaeus f.) RoyleHygrophila polysperma T. AndersonImperata brasiliensis TriniusImperata cylindrica (Linnaeus) Palisot de BeauvoisInula britannica LinnaeusIpomoea aquatica ForsskalIschaemum rugosum SalisburyLagarosiphon major (Ridley) MossLeptochloa chinensis (L.) NeesLimnophila sessiliflora (Vahl) BlumeLycium ferocissimum MiersLygodium flexuosum (Linnaeus) Swartz (maidenhair creeper)Lygodium microphyllum (Cavanilles) R. Brown (Old World climbing fern)Melaleuca quinquenervia (Cav.) BlakeMelastoma malabathricum L.Mikania cordata (Burman f.) B. L. RobinsonMikania micrantha KunthMimosa diplotricha C. WrightMimosa pigra L. var. pigraMonochoria hastata (L.) Solms-LaubachMonochoria vaginalis (Burman f.) C. PreslMoraea collina ThunbergMoraea flaccida (Sweet) SteudelMoraea miniata AndrewsMoraea ochroleuca (Salisbury) DrapiezMoraea pallida (Baker) GoldblattNassella trichotoma (Nees) Hackel ex ArechavaletaOnopordum acaulon LinnaeusOnopordum illyricum LinnaeusOpuntia aurantiaca LindleyOrobanche spp.Oryza longistaminata A. Chevalier & RoehrichOryza punctata Kotschy ex SteudelOryza rufipogon GriffithOttelia alismoides (L.) Pers.Paspalum scrobiculatum L.Pennisetum clandestinum Hochstetter ex ChiovendaPennisetum macrourum TriniusPennisetum pedicellatum TriniusPennisetum polystachion (L.) SchultesProsopis alapataco R. A. PhilippiProsopis argentina BurkartProsopis articulata S. WatsonProsopis burkartii MunozProsopis caldenia BurkartProsopis calingastana BurkartProsopis campestris GrisebachProsopis castellanosii BurkartProsopis denudans BenthamProsopis elata (Burkart) BurkartProsopis farcta (Banks & Solander) J.F. MacbrideProsopis ferox GrisebachProsopis fiebrigii HarmsProsopis hassleri HarmsProsopis humilis Gillies ex Hooker & ArnottProsopis kuntzei HarmsProsopis pallida (Humboldt & Bonpland ex Willdenow) KunthProsopis palmeri S. WatsonProsopis reptans Bentham var. reptansProsopis rojasiana BurkartProsopis ruizlealii BurkartProsopis ruscifolia GrisebachProsopis sericantha Gillies ex Hooker & ArnottProsopis strombulifera (Lamarck) BenthamProsopis torquata (Cavanilles ex Lagasca y Segura) de CandolleRottboellia cochinchinensis (Lour.) W. Clayon Rubus fruticosus L. (complex)Rubus moluccanus L.Saccharum spontaneum L.Sagittaria sagittifolia L.Salsola vermiculata L.Salvinia auriculata AubletSalvinia biloba RaddiSalvinia herzogii de la SotaSalvinia molesta D.S. MitchellSenecio inaequidens DC.Senecio madagascariensis Poir.Setaria pumila (Poir.) Roem. & Schult. subsp. pallidefusca (Schumach.) B.K. SimonSolanum tampicense Dunal (wetland nightshade)Solanum torvum SwartzSolanum viarum DunalSparganium erectum L.Spermacoce alata AubletStriga spp.Tridax procumbens L.Urochloa panicoides Beauvois

(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.

(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.

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

(2) Grass florets and caryopses classed as inert:

(i) Glumes and empty florets of weedy grasses;

(ii) Damaged caryopses, including free caryopses, with over one-half the root-shoot axis missing (the scutellum excluded);

(iii) Immature free caryopses devoid of embryo or endosperm;

(iv) Free caryopses of quackgrass (Elytrigia repens) that are 2 mm or less in length; or

(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) Seeds of legumes (Fabaceae) with the seed coats entirely removed.

(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) 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]