The pure seed shall include all seeds of each kind or each kind and variety under consideration present in excess of 5 percent of the whole. Seeds of kinds or kinds and varieties present to the extent of 5 percent or less of the whole may be considered pure seed if shown on the label as components of a mixture in amounts of 5 percent or less. The following shall be included with the pure seed:

(a) Immature or shriveled seeds and seeds that are cracked or injured. For seeds of legumes (Leguminosae) and crucifers (Cruciferae) with the seed coats entirely removed refer to §201.51(a)(1);

(b) Pieces of seeds which are larger than one-half of the original size. For separated cotyledons of legume seeds refer to §201.51(a)(2);

(c) Insect-damaged seeds, provided that the damage is entirely internal, or that the opening in the seed coat is not sufficiently large so as to allow the size of the remaining mass of tissue to be readily determined. Weevil-infested vetch seeds, irrespective of the amount of insect damage, are to be considered pure seed, unless they are broken pieces one-half or less than the original size. For classification of broken pieces of seed units one-half or less than the original size, refer to §201.51(a)(2). Refer to §201.51(a)(3) for chalcid-damaged seeds;

(d) Seeds that have started to germinate;

(e) Seeds of the cucurbit family (Cucurbitaceae) and the nightshade family (Solanaceae) whether they are filled or empty;

(f) Intact fruits, whether or not they contain seed, of species belonging to the following families: Sunflower (Compositae), buckwheat (Polygonaceae), carrot (Umbelliferae), valerian (Valerianaceae), mint (Labiatae) and other families in which the seed unit may be a dry, indehiscent one-seeded fruit. For visibly empty fruits, refer to inert matter, §201.51(a)(6);

(g) Seed units of the grass family listed in §201.47a(b) (1) through (5) if a caryopsis with some degree of endosperm development can be detected in the units, either by slight pressure or by examination over light. Seed units of smooth brome, fairway crested wheatgrass, standard crested wheatgrass, tall wheatgrass, intermediate wheatgrass, pubescent wheatgrass, western wheatgrass, fescues (Festuca spp.), and ryegrasses (Lolium spp.) if the caryopses are at least one-third the length of the palea; the caryopsis is measured from the base of the rachilla. Species in which determination of endosperm development is not necessary are listed in paragraphs (g) (1) and (2) of this section. Refer to §§201.48(h) and 201.51(a)(5) when nematode galls and fungal bodies have replaced the caryopsis in seed units. The following procedures apply to determine pure seed in the grass families listed below:

(1) Intact burs of buffalograss (Buchloe dactyloides) shall be considered pure seed whether or not a caryopsis is present. Refer to §201.51(a)(6) for burs which are visibly empty.

(2) The Uniform Blowing Procedure described in §201.51a(a) shall be used to determine classification of florets into pure seed or inert matter for Kentucky bluegrass, Canada bluegrass, rough bluegrass, Pensacola variety of bahiagrass, side-oats grama, blue grama, and orchardgrass.

(3) Special purity procedures for smooth brome, chewings fescue, red fescue, orchardgrass, fairway crested wheatgrass, standard crested wheatgrass, intermediate wheatgrass, pubescent wheatgrass, tall wheatgrass, and western wheatgrass are listed in §201.51a(b).

(4) For methods of determining pure seed percentages of annual and perennial ryegrass, refer to §§201.58(b)(10) and 201.58a(a).

(h) Seed units with nematode galls, fungal bodies (i.e. ergot, other sclerotia, and smut) and spongy or corky caryopses that are entirely enclosed within the seed unit. Refer to §201.51(c)(1) for inert matter classification.

(i) Seed units of beet and other Chenopodiaceae, and New Zealand spinach. Refer to §201.47a(g) and §201.51(a)(6) for definitions of seed units and inert matter, respectively.

(j) Seed units of forage kochia that are retained on a 1 mm opening square-hole sieve, when shaken for 30 seconds. For inert matter, refer to §201.51(a)(7).

[46 FR 53636, Oct. 29, 1981, as amended at 59 FR 64497, Dec. 14, 1994; 76 FR 31794, June 2, 2011]