On the morphological variation of Rafflesia cantleyi (Rafflesiaceae) on Pulau Tioman, Pahang, Peninsular Malaysia

In Peninsular Malaysia, Rafflesia is represented by seven species of which R. kerrii (and R. su-meiae) stands out distinctly from the other five. The other five species, R. azlanii, R. cantleyi, R. parvimaculata, R. sharifah-hapsahiae and R. tuanku-halimii, are collectively close enough to each other to be referred to as the R. cantleyi complex after its first-described species, R. cantleyi. Pulau Tioman has a population of R. cantleyi, which, because of its island location, is isolated from the mainland complex. This study was conducted to determine morphological variation in a selected location in Pulau Tioman. Twelve flowers were studied with respect to characteristics such as wart (blotch) pattern on perianth lobes, warts (dots) on upper surface of the diaphragm, shape of the aperture, shape of processes and types of ramenta. These are the characters that have been used to define species in the R. cantleyi complex. The variation in the local Tioman population was compared with the variation in the R. cantleyi complex on the mainland, which is about the same magnitude. This supports the idea that R. cantleyi is a single highly polymorphic species and that the species that have been described in the R. cantleyi complex should be reduced to varieties.