Research assistant Jeisin Jumian poses next to the rare Rafflesia keithii in the Silabukan Forest Reserve.
KOTA KINABALU (July 14): A Sabah Forestry Department stumbled upon a Rafflesia keithii in full bloom while conducting a forest inventory in the Silabukan Forest Reserve, some 50 km east of Lahad Datu.
Endemic to Borneo, R. keithii is the largest of three species of Rafflesias found in Sabah.
This new discovery is considered rare and exciting because the species has never been recorded this far east of Sabah, according to Dr Joan Pereira, a senior botanist at the Forest Research Centre in Sandakan.
The easternmost record of Rafflesia in Sabah is a lone record from the Danum Valley Conservation Area.
Botanical records show R. keithii occurring primarily on the west coast of Sabah (i.e. along the Crocker Range, Tambunan, Kota Marudu, and the Ranau area, including the Kinabalu Park) at altitudes ranging from 250-940 m.
The spectacular bloom in Silabukan measured 47 cm in diameter and was growing on volcanic soil at an altitude of 630 m.
An unopened Rafflesia bud was also observed next to the open flower, whilst another bud was found some 20 m away. The host plant of this parasitic species was identified as Tetrastigma diepenhorstii. All Rafflesias depend on host plants from the genus Tetrastigma.
The jubilant field team from the Forestry Department was carrying out a forest inventory in the Silabukan Forest Reserve as part of a collaboration with WWF Malaysia to establish a landcover monitoring system for the larger Tabin landscape, covering about 450,000 ha. Apart from providing information on floristic composition and soils, Datuk Frederick Kugan, the Chief Conservator of Forests said the Forestry Department expects to produce a high resolution carbon stock map for the Tabin landscape as an output of the inventory.
Kugan congratulated the field team for the interesting find, saying that it highlights the importance of the Silabukan FR as a Class I Protection Forest.