Hoya isabelchanae Rodda & Simonsson, a new, showy species of Hoya R.Br. (Apocynaceae, Asclepiadoideae) with pomegranate red flowers from Sulawesi, Indonesia

A new species of Hoya R.Br. from Sulawesi (Indonesia), H. isabelchanae Rodda & Simonsson, is described and illustrated. It is one of the largest flowered species in Hoya section Acanthostemma (Blume) Kloppenb. Its flowers are of comparable size to those of Hoya benchaii Gavrus et al., Hoya kloppenburgii T.Green, Hoya rundumensis (T.Green) Rodda & Simonsson and Hoya sigillatis T.Green ssp. sigillatis, all from Borneo. Among Sulawesi species it is compared with the vegetatively similar Hoya brevialata Kleijn & van Donkelaar and Hoya pallilimba Kleijn & van Donkelaar.