Ex Situ Propagation of Philippine Rafflesia in the United States: Challenges and Prospects


  • Jeanmaire Molina Long Island University Brooklyn
  • William McLaughlin United States Botanic Garden
  • Kyle Wallick United States Botanic Garden
  • Ronniel Pedales University of the Philippines
  • Viviane Marcella Marius
  • Danilo N. Tandang National Museum of the Philippines
  • Amor Damatac University of the Philippines
  • Nicole Stuhr University of Southern California
  • Susan K. Pell United States Botanic Garden
  • Theresa Mundita Lim Biodiversity Management Bureau
  • Ari Novy Leichtag Foundation




Rafflesiaceae, Cultivation


The large-flowered parasitic genus Rafflesia R.Br. (Rafflesiaceae) has long fascinated naturalists and scientists and is an iconic symbol for plant conservation. Techniques to effectively propagate members of the genus outside of their natural habitat are sparse, and grafting infected Tetrastigma K.Schum.(Vitaceae) host plants has previously been reported as a successful strategy for ex situ conservation of Rafflesia. Here we report our attempts in the United States to propagate host cuttings infected with Rafflesia speciosa Barcelona & Fernando and R. lagascae Blanco collected
from the Philippines, as well as uninfected host material. We also describe efforts to germinate R. speciosa seeds in vitro using various plant growth regulators (PGRs). After rooting, infected host cuttings survived for a maximum of 11 months, but did not produce shoots. However, an uninfected cutting of T. cf. magnum grafted onto an established Malaysian species of Tetrastigma in June 2017 has succeeded in the commencement of new growth. Three propagules of a second potential host, T. harmandii Planch., have also been vigorously growing at the United States Botanic Garden since June 2017. However, Rafflesia seeds did not germinate with the application of PGRs, even though the seeds were viable according to tetrazolium (TZ) testing.

These ex situ propagation attempts have revealed challenges in propagating these species outside of their native ranges, but our incremental success in rooting infected Tetrastigma, as well as grafting interspecific Tetrastigma species, bodes well for further advances. With Philippine host species, T. harmandii and T. cf. magnum in cultivation, we can begin using these specimens for future experimentation involving grafting of infected material and Rafflesia seed inoculation trials.

Furthermore, we describe new avenues of propagation techniques for Rafflesia as practised by Marius Gabin, one of the owners of the Vivian Rafflesia garden, which contains a natural Rafflesia forest habitat at Poring Springs, Sabah, Malaysia. Gabin openly shared his successes in artificially inoculating Rafflesia seeds into a mature Tetrastigma vine. Gabin’s willingness to share his experience highlights the importance of collaborating with practitioners who have developed local knowledge of Rafflesia horticulture and conservation.

Author Biographies

Jeanmaire Molina, Long Island University Brooklyn

Assistant Professor

William McLaughlin, United States Botanic Garden

William McLaughlin is a Plant Curator at the United States Botanic Garden

Kyle Wallick, United States Botanic Garden

Kyle Wallick is a Botanist at the United States Botanic Garden

Ronniel Pedales, University of the Philippines

Ronniel Pedales is a University Research Associate at the University of the Philippines

Viviane Marcella Marius

Viviane Marcella Marius is a local entrepreneur

Danilo N. Tandang, National Museum of the Philippines

Danilo N. Tandang is a Museum Researcher at the National Museum of the Philippines

Amor Damatac, University of the Philippines

Amor Damatac II is a University Research Associate at the University of the Philippines

Nicole Stuhr, University of Southern California

Nicole Stuhr is a PhD student at the University of Southern California

Susan K. Pell, United States Botanic Garden

Susan K. Pell is Deputy Executive Director of the United States Botanic Garden

Theresa Mundita Lim, Biodiversity Management Bureau

Theresa Mundita Lim is Director of DENR – Biodiversity Management Bureau (BMB)

Ari Novy, Leichtag Foundation

Ari Novy is Chief Scientist at the Leichtag Foundation


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How to Cite

Molina, J., McLaughlin, W., Wallick, K., Pedales, R., Marius, V. M., Tandang, D. N., … Novy, A. (2017). Ex Situ Propagation of Philippine Rafflesia in the United States: Challenges and Prospects. Sibbaldia: The International Journal of Botanic Garden Horticulture, (15), 77–96. https://doi.org/10.24823/Sibbaldia.2017.224