Mass. Gen. Laws ch. 128 § 93
No person shall be subject to the penalties of section one hundred for having sold or offered or exposed for sale in the commonwealth any agricultural, vegetable, flower or tree and shrub seeds which were incorrectly labeled or represented as to kind, variety (cultivar) or origin, which seeds cannot be identified by examination thereof, unless he has failed to obtain an invoice or grower's declaration or other labeling information giving kind, variety or origin, if required, and to take such other precautions as may be necessary to insure the identity to be that stated.
The labeling requirements for all vegetable and agricultural seeds, including mixtures, flower and tree or shrub seeds shall be considered to have been met if the seed is taken from a properly labeled container in the presence of the purchaser.
Mass. Gen. Laws ch. 128, § 93