Three new species and a new hybrid of Rhododendron sect. Vireya (Ericaceae), recently discovered in New Guinea, are described and illustrated. R. tintinnabellum Danet, sp. nov. differs from R. revolutum Sleumer by having longer leaves and a white, campanulate corolla. R. evelyneae Danet, sp. nov. Differs from R. spondylophyllum F.Muell. by having erect, strongly revolute leaves and a tubular, 5-saccate corolla. R. kawir Danet, sp. nov. differs from R. opulentum Sleumer by having pseudoverticillate leaves, a less visible leaf venation and a lepidote corolla, and differs from R. rappardii Sleumer by having larger flowers and anther cells that are rounded at the base. R. °— nebulicolum Danet, nothosp. nov. appears to have resulted from the natural hybridization between R. brassii Sleumer and R. versteegii J.J.Sm.
Ericaceae, Rhododendron, Vireya, New Guinea, Indonesia, new species, new hybrid