The Ayahuasca Patent – A Case Study of US Plant Patent 5,751 and Biopiracy

In 1974, a Field Museum botanist pressed a vine onto a herbarium sheet and noted that its flowers were ‘deep pink turning white with age’. Ten years later, an American businessman patented the same plant in Washington, claiming as novel a flower that was ‘rose coloured fading to near white with age’. The patent stood for seventeen years.

1974 Diverging Records of Ayahuasca and Patent Law

Loren Miller travelled to the Ecuadorian Amazon in 1974. He was founder of the California-based International Plant Medicine Corporation. A tribal leader gave him a cutting of the Banisteriopsis caapi vine, the plant Amazonian communities know as ayahuasca or yage.

Miller carried the live cutting back to the United States. He has never named the community that handed it over, citing security concerns.

In the same year, Dr Timothy Plowman pressed his own Banisteriopsis caapi specimens into herbarium sheets. Working with Jon H. Martin, he catalogued one as ‘Martin & Plowman 1805’ and deposited it in the Field Museum of Natural History in Chicago. On the mounting board he wrote, in his own hand, that the flowers were ‘deep pink turning white with age’.

That sheet sat in the Chicago archive, publicly accessible, for the next quarter of a century.

Miller filed his first patent application in 1981. The seven-year gap matters as collecting the plant and seeking patent protection were separate decisions, made years apart.

Back at the patent office, the first filing was rejected as ‘informal and failing to present a written description in clear, concise, and exact terms’. Miller, by the patent office’s own internal account, did not know how to prosecute a patent. He had to find better help.

The Patent Filing and Da Vine Novelty Claims

Miller’s final filing landed at the patent office on 7 November 1984. He named the variety ‘Da Vine’. Its claim to novelty rested on flowers ‘rose coloured fading to near white with age’.

The filing also described medicinal uses, including a claim that the plant could treat post-encephalitic Parkinsonism.

US Plant Patent 5,751 was granted on 17 June 1986. James R. Feyrer was named as primary examiner of record. Miller received seventeen years of exclusive control over the asexual reproduction of the vine inside the United States.

Eight months before the grant, the patent office’s own approved bibliography included the 1982 Gates monograph. Gates described the species’ petals as ‘pale pink, becoming pale yellow in age’.

The 1999 Patent Challenge Using Prior Art to Fight Biopiracy

Amazonian Indigenous organisations appear to have remained unaware of the patent until 1994.

Two years later, the Coordinating Body of Indigenous Organisations of the Amazon Basin, representing more than four hundred indigenous groups across eight countries, declared Miller an enemy of indigenous peoples and barred him from entering their territories. Sources differ on whether the declaration was issued in 1996 or 1998.

On 30 March 1999, the Center for International Environmental Law and the Coalition for Amazonian Peoples filed a formal request for re-examination at the United States Patent and Trademark Office. They could not argue the patent was wrong in principle. The system did not accept that kind of argument.

What they could submit was prior art (existing public knowledge or published writing that proves an invention is not genuinely new). They sent the patent office the Martin & Plowman 1805 sheet, with Plowman’s twenty-five-year-old handwritten ‘deep pink turning white with age’ note in plain view on the mounting board.

On the basis of that single sheet, the patent office rejected the patent in autumn 1999. The Office Action was dated 3 November 1999. With it, the novelty argument based on flower colour could no longer hold.

The reversal lasted seventeen months.

The 1912 Colour Standard

A book printed in 1912 became central to saving the patent.

Between February and May 2000, Miller filed written rebuttals to the autumn 1999 rejection. He did not contest the species identity. The argument turned on whether Plowman’s notes legally established identical traits.

That book was ‘Ridgway’s Colour Standards and Colour Nomenclature’, published in 1912 by an American ornithologist named Robert Ridgway. It was a catalogue of named colour chips originally intended to help bird taxonomists describe feather plumage with consistent vocabulary.

Plowman, writing on a herbarium sheet in 1974, had not used the Ridgway book.

In January 2001, the examiner agreed that Miller’s arguments were ‘unpersuasive in and of themselves’. But on the specific question of whether the Plowman notes proved identical flower colour, the examiner ruled they did not.

On the question of whether the plants matched, the examiner did not concede. He wrote that ‘there is no evidence to indicate, let alone prove‘ that the flower colouration in the two specimens was identical, and pointed to the 1982 Gates monograph as evidence of variation in the species.

CIEL’s lawyers later read the same ruling as ‘tacit agreement’ that the colours did match, and that only the Plowman vocabulary had failed the procedural test. That is an interpretation, not the transcript. The transcript disputes the match.

Reexamining the Patent From Flower Colour to Leaf Morphology

The May 2000 telephone interview is the moment the record breaks. No transcript of the call between Examiner Feyrer’s office and Miller’s attorney has surfaced. Internal records confirm only that the two parties discussed how Miller might overcome the rejection.

Days later, Miller requested an extension of time. He used the extension to assemble a new comparison. Flower colour, on which the original 1986 grant had relied, was dropped from the argument.

The case became about leaves.

Karen Shigamatsu, a staff member at the Lyon Arboretum in Hawaii, sent in the leaf used for comparison. It arrived dried and pressed. Feyrer placed it next to the Plowman herbarium sheet from Chicago.

In January 2001, the examiner ruled that Da Vine had ‘a comparably greater length to width ratio, while being slimmer and smaller in overall size, and the adult foliage having a more acuminate tip’. An acuminate tip is one that tapers to a long, narrow point.

A Notice of Intent to Issue a Reexamination Certificate followed. In April 2001 the formal certificate was issued. The patent stood for the remainder of its statutory term and expired on 17 June 2003.

Two records would close the gap. The May 2000 transcript, and the chain-of-custody paperwork that could establish the provenance of the Hawaii specimen and its relationship to the plant collected in Ecuador in 1974.

The 1930 Plant Patent Act and Failure to Recognise Indigenous Agriculture

The 1930 Plant Patent Act, codified at 35 U.S.C. ch. 15, was written for American commercial fruit growers and rose breeders. It required the patented plant to be intentionally cultivated rather than picked from the wild. The statute did not account for Amazonian systems of cultivation.

Miller’s filing met that cultivation requirement with a single sentence. His patent claimed the plant was ‘discovered growing in a domestic garden in the Amazon rain-forest of South America’. No garden owner is identified on the filing. The village is unnamed. No garden owner, village, coordinates or cultivator is identified.

That phrasing did two contradictory things at once. Satisfying the 1930 statute required cultivation. At the same time, the people responsible for that cultivation disappeared from the legal description.

Indigenous claimants who wished to defeat the patent by arguing the vine was wild had to legally deny their own centuries of selective breeding and forest management. If they argued the plant was cultivated, they conceded the very ground the patent stood on.

The bind was structural. Congress had simply not written a category for the agriculture being practised in the Amazon basin.

Schultes’ 1986 field notes, published in the Journal of Ethnobiology, documented Northwest Amazon communities deliberately selecting and propagating Banisteriopsis varieties for medicinal use. Miller’s patent file does not reference Schultes. Neither did the 1999 re-examination.

Why Indigenous Oral Knowledge Did Not Count

Under American patent statute at the time, prior art had to be a printed publication, or evidence of public use within the United States. The relevant section was 35 U.S.C. §102. Anything else did not count.

Centuries of indigenous oral practices across the Amazon basin had been documented by ethnobotanists and anthropologists. Legally, the practice itself was invisible to the patent system. Oral knowledge practised outside the United States therefore had no direct route into the prior-art analysis.

Even the printed records were poorly connected. The 1981 to 1986 examination at the patent office ran on databases of prior patents and approved botanical journals. Ethnographic archives and herbarium catalogues at institutions like the Field Museum sat in their own filing systems, unconnected to the patent search infrastructure.

A patent examiner sitting in Washington in 1985 could not query the Chicago herbarium catalogue from his desk. The Plowman sheet was publicly accessible to anyone who walked into the museum. From the examiner’s desk, the catalogue was invisible.

The re-examination procedure compounded the problem. CIEL’s lawyers filed the challenge and were then locked out. Ex parte re-examination, the only route available to outside challengers at the time, removed them from the room after the initial filing.

The remaining examination proceeded between the patent owner and examiner. That May 2000 telephone interview is the document we do not have.

Source Box

Sources include: US Plant Patent 5,751, USPTO (granted 17 June 1986; re-examination certificate April 2001); analyses by the Center for International Environmental Law, including ‘PTO Decision Analysis’ and ‘PTO Examiner Transcript’ (2001); Bosse, ‘Re-examining the “wild” story of the ayahuasca plant patent’, Queen’s University Belfast (2024); the Martin & Plowman 1805 herbarium sheet held at the Field Museum of Natural History, Chicago (1974); Schultes, ‘Recognition of Variability in Wild Plants by Indians of the Northwest Amazon’, ‘Journal of Ethnobiology’ Vol. 6 No. 2 (1986); Tahdooahnippah, ‘The “Ceremonial Use” Defense to Infringement of Psychedelic Patents’, ‘Berkeley Technology Law Journal’ Vol. 39 No. 2 (2024); and ‘Traditional Knowledge Digital Library: A Magic Bullet in the War Against Biopiracy’, San José State University ScholarWorks.