Rafflesia philippensis is a parasitic plant species of the genus Rafflesia that was named by Blanco in his Flora de Filipinas in 1845. R. philippensis is known only from a mountain located between the provinces of Laguna and Quezon, Luzon where it was first discovered. Its plant host is Tetrastigma pisicarpum. This species went unnoticed since its first description by Blanco but was rediscovered in 2003 by members of the Tanggol Kalikasan, a local environment conservation group in Quezon province who first saw and photographed the open flower of this species. It was brought to the attention of Manuel S. Enverga University (MSEUF), who formed a team composed of students and faculty to document the newly discovered Rafflesia species.