I've never seen this behaviour on a rhodo before. Something about it reminds me of leaf galls on azaleas though the leaves in the pictures are not swollen and fleshy. Can anyone identify what's happening here? And should I be worried? John
Thanks Michael. An initial wikipedia search of phytoplasma lead to phyllody which is often caused by phytoplasmas but can also be caused by environmental stresses causing hormonal changes. If some of the blooms instead of all the blooms are affected it could be environmental. I'll take a look at conditions around the plant to begin with. In my quick read though, nothing was said about what to do with the growths or with the plant.
First of all I would cut and dispose of the branches with abnormal growth. They look bad and they harbor the disease.