strange raised black areas on Catt Mac holmes leaves
 

I bought a mac holmes "Newberry" In August of last year and it has done fairly well new leads and roots and getting larger .......BUT
a couple of leaves had a blackened area ate the base of the leaves where they joined the Pbs.It lookes roughened and abraded and I originaly did think it was a area that had had a fungau and that the nursery had treated it and it was simply disfigured and ok....


This same plant deveoped a few black spots I thought were fungal in nature I treated and removed affected parts and thought I had it gone....BUT again I have black areas appearing.This time on a pbs that developed as a bifoliate growth and the black has appeared at the base of the leaf where it joins the Pbs just as it was on older leaves when I bought the plant.

I removed the smaller of the leaves on the bifoliate growth by grasping it and snapping it off at the juncture so I could look at it closer before going to the drastic measure of taking the entire growth off or ....derstroying the plant I am still considering this if I can not find a good answer to this stuff



Ok enough rambling in my question ....My question is and I have no pictures to show so description will have to do what coulkd this be ......it appears as raised rough black areas not bacterial it actually looks more like a canker very rough and thickened areas and pure black.
It could be compared to a large wart almost