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| Rafflesia banaoana Malabrigo (A.B.Tobias, Thorogood & Malabrigo), in Tobias, Thorogood & Malabrigo, 2023. |
Abstract
The Southeast Asian genus Rafflesia (Rafflesiaceae) is famous for possessing the world's largest flowers. All species are rare or threatened, so understanding taxonomic diversity in the genus is crucial for informing effective conservation practice. Here we examine R. banaoana, a poorly known taxon from the remote montane rainforests of the Kalinga Province in the Philippines. This species has been treated as conspecific with R. leonardi, and overlooked in systematic studies. Using stable yet hitherto neglected features such as the stigmatic fascia surface, disk shape, process structure, annulus interior and exterior distinction, and ovary shape, we demonstrate that R. banaoana is morphologically as well as ecologically distinct from R. leonardi, and requires reinstatement at the specific rank. We present our findings in the broader context of complexity in the genus Rafflesia in the Philippines, now considered the center of diversity, with 15 species described to date. We highlight the taxonomically confused R. banaoana as a case for careful observation of previously unexamined morphological characters, as well as ecology, to avoid overlooking cryptic taxa or species complexes and to inform representative sampling in systematic treatments. Such an approach will be essential for enhancing our understanding of the diversity of this enigmatic yet poorly understood genus at a time of unprecedented anthropogenic change and species extinction. In light of our findings, we recommend a holistic approach to the conservation of Rafflesia in the Philippines.
Keywords: biodiversity conservation, endemic, IUCN Red List, parasitic plants, Rafflesia leonardi, Eudicots
Adriane B. Tobias, Chris J. Thorogood and Pastor L. Malabrigo Jr. 2023. The Reinstatement of Rafflesia banaoana (Rafflesiaceae), and Implications for Assessing Species Diversity and Conservation Requirements of the World's Largest Flowers. Phytotaxa. 612(2); 201-216. DOI: 10.11646/phytotaxa.612.2.5
P.L. Malabrigo, Jr. 2010. Rafflesia banaoana (Rafflesiaceae): another new species from Luzon, Philippines. Asia Life Sciences-The Asian International Journal of Life Sciences. Suppl. 4: 139–146.
https://parasiticplants.siu.edu/RaffPhil/RaffPhilLit/Malabrigo2010RaffBanaoana.pdf
Etymology. The species is named after the very hospitable and environment-friendly people in Kalinga, the Banao Tribe, whose traditional forest management practice is exemplary. The people of Banao have kept a good forest status of Kalinga for having the least reduction of old-growth forests among the provinces of Cordillera Administrative Region. The most recent forest survey showed that old-growth forests cover more than 85% of the total BBNP area. Further, the locality where the population was discovered is part of the Banao watershed inside the Balbalasang-Balbalan National Park (BBNP).
