JARS v41n3 - Rhododendron tuba

Rhododendron tuba
Hilda Crouch
Mt. Helen, Victoria, Australia

Rhododendron tuba (Sleumer) - A shrub approximately 12 feet high, leaves coriaceous, ovate, glossy dark green, almost sessile, sub-acute, midrib very prominent and wide at base, veins prominent above. Flowers in terminal umbels averaging seven per truss. Long tube 4-5" straight, but curved in bud, pink, deeper at base. Corolla lobes opening wide to slightly reflexed, white. Stigma protruding inch, stamens yellow about equal to tube.

R. tuba
Photo by Leonie Borch

This species is only to be found on Mt. Dayman, Papua, New Guinea, on Manaeo peak at approximately 9000 feet. It grows in shrubbery on the edge of a patch of elfin wood just below the summit on the northern side of the mountain. A single plant was found on Donana Peak at 8,000 feet.
It has been suggested the R. tuba is a hybrid between R. cruttwellii and R. rhodoleucum as both grow near, but against this is the argument that it is a patch of many plants and that it is quite homogenous and distinct.
In the central west of the State of Victoria at 1600 feet our two plants of R. tuba , now some ten years old, have been blooming towards the end of August each year for the last 5-6 years. It has been our experience that they will only bloom every second year, but make good growth in between and very conveniently, our two plants bloom in alternate years. The flowers are of good substance, perfumed, and last three weeks or more as a good garden plant. We can highly recommend this species. Each has formed a compact shrub, the present height now around 3 feet. They receive the speckled shade from our high eucalypts which also give frost protection. Our only treatment is the addition of heavy mulch from shreddings, mostly of eucalypt material.