§ 361.6 Noxious weed seeds. ( 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 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 ) 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]