Hoya wongii (Apocynaceae, Asclepiadoideae): a new campanulate flowered species from Brunei (Borneo)

A new species from kerangas heath forest of Brunei, Borneo, Hoya wongii, is here described and illustrated. This species differs from the previously described species of Hoya in having a corona with inflated outer processes and laterally compressed and erect inner processes, ending in two bidentate membranaceous appendages. The corona is inserted above a pale yellow campanulate corolla. We discuss morphological affinities between the new species and other campanulate flowered species of Hoya.