For the purposes of this article, the term:

(1) "Certified seed" means the progeny of foundation, registered, or in special cases certified seed which meets the standards of the official seed certifying agency.

(2) "Foundation seed" means the progeny of breeder's seed or in special cases the progeny of foundation seed which meets the standards of the official seed certifying agency.

(3) "Plant" means seedlings, nursery stock, roots, tubers, bulbs, cuttings, and other parts used in the propagation of field crops, vegetables, fruits, flowers, trees, or other plants.

(4) "Registered seed" means the progeny of foundation seed and meets the standards of the official seed certifying agency.

(5) "Seed" means the true seeds of all field crops, vegetables, flowers, trees, or other plants.

(6) "Variety" carries its original meaning and includes "strains" of varieties which are sufficiently different from the parent variety to justify special designation.