For many years, Rhododendron lochiae was considered to be Australia's only native Rhododendron, only found growing within the Bellendron Kerr Range inland from Cairns. However, recent investigations have indicated that two distinct species exist. The second species, Rhododendron notiale which occurs in the same geographical area as Rhododendron lochiae, was recognised in 1996. R. notiale is different from R. lochiae in that the shape of the flower tube is curved rather than straight. It should be noted that the validity of the second species has not yet been fully accepted by the botanical community (see Australian Plants Vol 22, No. 175 pages 59 -60.)
To grow Rhododendron lochiae successfully, you will need a raised bed with moist, acid soil with a high organic content to mimic their natural high mountain north Queensland rainforest conditions.
I planted mine about 25 years ago in my garden (in the northern Sydney suburb of Westleigh) and they are now approximately one metre high and about the same wide -- yes they are slow growing.
They receive only dappled morning sun and shade for the rest of the day. My plants are happier with some supplementary watering as they flower better and after good soaking rains I am rewarded with a mass display of flowers from late spring through to autumn. The flowers are about 50mm long by 30mm across and occur in terminal clusters of up to six flowers, although the best my plants can do is four flowers. Perhaps my growing conditions are not ideal.
Rhododendron: is from the Greek rhodon, rose and dendron, tree, in reference to the terminal flower clusters.
lochiae: named by Ferdinand Mueller after Lady Loch who was the wife of Sir Henry Brougham Loch, who was Governor of Victoria 1884-89.