New Blog Series – Agritech Thymes: A brief look at public prior use of plants in the US

In the US, plants can be protected by utility patents, plant patents and/or plant variety rights. Both types of patent are subject to the same novelty rules of USC §102, which states that public prior use counts as a disclosure which can destroy the novelty of an invention.

In a decision from the Federal Circuit in the US in 2023 relating to a utility patent application on a particular plant variety, it was held that merely having a new plant variety on display to the public and labelled with its variety name before the filing date is a citeable public prior use of the plant.

This case¹ related to the US utility patent for a variety of Calibrachoa plant named ‘Cherry Star’ having a distinctive star pattern on the petals. Claim 1 defined the variety by said pattern as follows:

‘A Calibrachoa plant comprising at least one inflorescence with a radially symmetric pattern along the center of the fused petal margins wherein said pattern extends from the center of the inflorescence and does not fade during the life of the inflorescences, and wherein the Calibrachoa plant comprises a single half-dominant gene, as found in Calibrachoa variety ‘Cherry Star,’ representative seed having been deposited under ATCC Accession No. PTA-13363’.

The applicant sought a reissue of the patent, and during the examination process of said reissue application, they disclosed that the variety had been had displayed at a Home Depot store event, where the public were able to view it. The applicant argued that the novelty was not destroyed by displaying the plant because the public did not have possession of the genetics of the plant to enable it to be bred, and were not aware that Cherry Star was the result of a “single half-dominant gene” as claimed. The PTAB examined “whether the purposed use: (1) was accessible to the public; or (2) was commercially exploited”, and held that although the variety wasn’t sold or analysed by the public, because the intended use of the plant variety is ornamental and its petal pattern was seen, that this was a citeable disclosure.

The federal circuit have only once before considered prior use in the context of plants, back in 2015. This earlier US decision² related to two plant patents for ‘Scarlet Royal’ and ‘Autumn King’ table grapes in which the variety was grown in public before filing, but in this case, the variety was not identified and the intended use of the plant was for consumption rather than ornamental. The court confirmed that the “grape varieties cannot be reliably identified simply by viewing the growing vines alone.” As such in that case, the disclosure was not deemed to be novelty-destroying. It seems that perhaps if the cherry star was not identified as such by the labelling, their case may have been stronger. Furthermore, it seems that arguments could have been presented around the feature of the claim that the pattern ‘does not fade’ which would not have been made available to the public at the short event.

This case somewhat surprisingly shows that in situations where the use of the invention, even under a utility patent, is one of an aesthetic or visual nature then displaying it can be enough to destroy novelty by prior use in the US. A reminder that patent applications should always be filed before disclosure, and relying on technical genetic features of plant claims may not be enough to ensure novelty over prior use.

This article was prepared by Partners Punita Shah and Ellie Purnell.