No abstract

Ramentae are hair-like structures found on the perigone tube and diaphragm in species of Rafflesia (Rafflesiaceae). Although ramenta morphology provides an important taxonomic character, a consistent terminology has not been used in species descriptions. As such, morphological comparisons among species as well as among populations within a species are difficult. We used a variety of resources to document the morphology including the location and density of ramenta among 18 species of Rafflesia and between populations and/or sexes of two species. We identified five types of ramenta: tuberculate, filiform, swollen apex, toadstool, and fence-like and recognized several variations within each type. Ramenta types characterize four species complexes: R. patma (tuberculate), R. arnoldii (filiform), R. pricei (mostly swollen apex), and R. hasseltii (mostly toadstool). Our classification of ramenta offers a tool for using consistent terminology to re-evaluate previously described species and to define new species of Rafflesia.

The new species Rafflesia parvimaculata is described from Pahang, Peninsular Malaysia. This species is characterized by its numerous small white warts on the perigone lobes, and also by its slender, unbranched, capitate ramenta that are white in color and densely arranged inside the floral perigone tube. These unique characters distinguish R. parvimaculata from other Rafflesia species. The discovery of this new species brings the total number of Rafflesia species described from Peninsular Malaysia to five