Found only in Southeast Asian rainforests, the Rafflesia genus produces the worlds largest flowers. Their prodigious size is no small feat, considering that Rafflesia possess neither roots, leaves nor stems. They are also incapable of photosynthesis, relying entirely on their hosts (certain species of Tetrastigma vines) for nourishment. These parasitic plants remain one of botanys biggest mysteries. The gaps in knowledge about Rafflesia have created a considerable challenge for conservationists scrambling to save them, particularly in the Philippines, which scientists consider to be one of the few centers of Rafflesia diversity. Threats to Rafflesia conservation in the Philippines Due to their rarity and extremely small habitat range, Rafflesia are infamously difficult to study. Experts have failed to grow Rafflesia plants ex situ outside of their host vines, says Erika Marie Bascos of the University of the Philippines Dilimans Institute of Biology. Unlike nonparasitic plants, Rafflesia cannot be readily propagated via cuttings, seeds or tissue culture, she told Mongabay, adding that Rafflesia have only been successfully propagated by grafting infected vines or implanting seeds into uninfected hosts, methods that take a very long time to yield results. Rafflesia banaoana in Kalinga province, northern Luzon, one of the Rafflesia species found in the Philippines. Image courtesy of Adriane Tobias. Meanwhile, the clock is ticking, as all Rafflesia species are inching closer toward extinction. Habitat destruction is a major threat, even in cases of small-scale land conversion. According to Esperanza Maribel Agoo, a professor from the Biology Department of De La Salle UniversityThis article was originally published on Mongabay