Rhododendron loranthiflorum Sleumer is a tropical, epiphytic, Vireya species with white perfumed flowers found on the island of Bougainville in the Solomon Islands at an altitude of about 1000m. In Melbourne, a number of specimens have been growing out of doors in the garden of John Rouse for the last 25 years. One particular clone is outstanding in that it is easily cultivated, grows as a dense shrub and is highly floriferous with some flowers to be found at most times of the year. Here we give a brief introduction to the species and its natural habitat and describe our outstanding specimen that has been named after the New York Guru Sri Chinmoy to honour his international endeavours to attain world peace.
The tropical vireyas are naturally distributed in the equatorial region bounded by the Philippines in the north, Sumatra and Peninsular Malaysia in the west, North Queensland in the south and the Solomon Islands in the east, with a concentration of species diversity found on the islands of New Guinea and Borneo. These two regions of species concentration are separated by Wallacea (Wallace, 1869), the biologically discontinuous region which contains the line of join between Eurasia and the Australian plate when they collided some 10 million years ago and brought together their own groups of animals and plants. The tropical vireyas, which probably arose from a wandering Himalayan ancestor, have developed over the past three or four million years with considerable isolation between the species east and west of Wallacea. Mostly, the tropical vireyas are found in the mountains at altitudes of 1000 to 4000m above sea level, so while day and night times are equal the year round and relative humidity is high, the temperature is lower than that at tropical sea level. Rhododendron loranthiflorum is a scaly species in subgenus Rhododendron, section Vireya, subsection Solenovireya (Sleumer, 1966). This subsection contains over 30 species spread out from Sumatra and Peninsular Malaysia to Bougainville but excluding Java and Australia. Their characteristics include well spread out flowers with a tubular corolla and a relatively long, straight or slightly curved tube. This collection of species appears to lack cohesion in that their diverse properties suggest that they should be divided into two or more taxa (Stevens, 1985; Williams and Rouse, 1997).