UP biologists discover new giant flower found only in the Philippines

A new species of Rafflesia, with an average diameter of 9.73 centimeters has been discovered by a team of UP biologists near the Pantabangan Masiway Hydroelectric Power Plant (PMHEP) in Nueva Ecjia.  This amazing new discovery now holds the world record of being the smallest among giant flowers. Named Rafflesia consueloae, this new species has been published in the open access journal Phytokeys last (date of publication). The Rafflesia consueloae is found only in the Philippines and so far thrives in only two sites in the Pantabangan watershed area.

The Rafflesia is a parasitic plant which can reach up to 1.5 meters in diameter. As such, the world’s largest flowers naturally belong to Rafflesia.

Rafflesia consueloae with its immaculate surface a few minutes after full bloom (Photo credit: Biodiversity Research Laboratory, UP Biology)

Side view of the giant flower (Photo credit: Edwino S. Fernando)

The new species has been classified as critically endangered, based on IUCN’s (International Union for the Conservation of Nature and Natural Resources) criterion of a species having less than 100 km2 of extent of occurrence with its two small populations. The continued protection of this species is important as it is part of the biodiversity of the area. The survival of this species is threatened by wildlife hunting and forest fires during the dry season.

R. consueloae was found in two localities, Mt. Balokbok and Mt. Pantaburon in Nueva Ecija, that are two kilometers apart and within the Pantanbangan-Carranglan Watershed where the Pantabangan Hydroelectric Dam is located. It is currently operated by First Gen Hydro Power Corp (FGHPC).  

FGHPC together with the Institute of Biology (UP Biology) of the University of the Philippines Diliman and the Diliman Science Research Foundation (DSRF) had been undertaking a long-term biodiversity conservation monitoring program in the watershed as part of its commitment to understand and protect the watershed, biodiversity and the environment in general. The biodiversity monitoring program commenced in March 2011 while the Rafflesia monitoring began immediately after its discovery in February 2014 and continues to this day.

First Gen chairman and CEO Federico R. Lopez lauded the efforts of these scientists, fully aware of the hardships and sacrifice associated with such research and studies. 

 “The Philippines is blessed with so many amazing living things that, even in this day and age, the world of science isn’t yet aware of. We’re thankful the country has researchers and scientists at UP Institute of Biology who dedicate their lives to unlocking the mysteries of these enigmatic species for all of us. It’s really a privilege for us to be working closely with such committed men and women and their work truly deserves everyone’s support.” 

The new species is named Rafflesia consueloae in honor of Mrs. Consuelo ‘Connie’ Rufino Lopez, lifelong partner of Filipino industrialist Oscar M. Lopez and mother of Federico R. Lopez.

“With her demure, but strong personality traits, which Rafflesia consueloae also possesses, she provides the inspiration for Mr. Lopez’s pursuit of biodiversity conservation in the Philippines,” said Professor Perry S. Ong of UP Biology and DSRF, lead researcher of the study.

Aside from UP Biology and the DSRF, the Department of Forest Biological Sciences (UPLB FBS) of the University of the Philippines Los Banos also helped in the research.

R. consueloae population 11 days after discovery. The pink flags indicate where Rafflesia consueloae in various stages of development and decay are located. More than 160 individuals were counted in this sub-site alone. (Photo credit: Biodiversity Research Laboratory, UP Biology)

Prof. Ong described the discovery of the new species near the Pantabangan Masiway Hydroelectric Power Plant as serendipitous, when a field assistant accidentally kicked over a pile of forest litter, exposing a decayed flower of R. consueloae.  

Prof. Ong said that to illustrate how small the Rafflesia is, one could line up 15 fully bloomed flowers of R. consueloae tip to tip, and spread it on top of and across a single fully bloomed flower of R. arnoldi and it would still not be enough to cover it. A full bloom R. consueloea measures about 10 cm x 10 cm x 10 cm, about the size of a baseball. 

The newly described Rafflesia consueloae with a ruler behind it to demonstrate its size (Photo credit: Edwino S. Fernando)

The record of the largest flowers in the worldbelongs to Rafflesia arnoldi from Sumatra and Borneo, which can grow up to a diameter of 1.5 meters.  In the Philippines, Rafflesia schadenbergiana, found only in Mindanao, is still large witha flower diameter of 0.8 meters.  Co-author Professor Edwino S. Fernando of UPLB FBS added that Rafflesia consueloae is the sixth species from Luzon Island and the 13th for the entire Philippine archipelago.   

Rafflesia flowers are unique in that they are entirely parasitic on roots and stems of specific Tetrastigma vines in the forests and have no distinct roots, stems, or leaves of their own,” explains Prof. Fernando. “Thus, they are entirely dependent on their host plants for water and nutrients.” 

Another characteristic of R. consueloae is that its flowers do not have the distinct odor common to Rafflesias. Its fruit, in fact, has the smell of a young coconut meat. 

Through the installation of motion activated camera, the research team was able to document different parts of the life cycle of the R. consueloae year round. Subsequently, additional observations were done to further understand its life cycle. 

Researcher John Michael Galindon of UP Biology and DSRF, another co-author, observed that the flowers can only be found in the roots of an unidentified species of Tetrastigma, a vine that belongs to the grape family.  He further noted that not all Tetrastigma vines have Rafflesia buds, much more flowers, while a single vine can have multiple flowers in various stages of development. 

According to Prof. Ong, considering how tough the bark of Tetrastigma is, how tiny Rafflesia seeds penetrate the tough Tetrastigma vines to complete its life cycle, remains a mystery. This is just one of many mysteries regarding the biology of Rafflesia in general and of R. consueloae in particular, that will be the subject of continuing research. 

While male and female flowers of R. consueloae have been found, some individual flowers have been encountered to contain both male and female parts, whether these are functional or not is part of that mystery that needs to be unlocked, Prof Fernando further added. 

Meanwhile, the Department of the Environment and Natural Resources – Biodiversity Management Bureau (DENR-BMB) in partnership with UP Biology is undertaking the Wildlife Forensics and DNA Barcoding of Philippine Biodiversity Program, which is now currently studying the DNA barcode of R. consueloae and its host Tetrastigma, the species of which remains unidentified.

The new discovery has also been featured on the New York Times and the Philippine Daily Inquirer.

Article written by Mariano Roy M. Duya, teaching fellow at the UP Diliman Institute of Biology