Mutant? cane on Irene Watts/Pink Gruss
So I'm out pruning IW/PG and spot a strange cane. Where the other canes are smooth and brownish, this cane is flattened with some random unpleasant grey thorns. Yet, up at the top it appears to be branching out and growing normally. The cane is quite light (I pruned it off) and is green mottled with brown. It's quite healthy. I've never seen a rose cane like this: we're talking very flat. Looking at it from its side, it's 1 inch wide by 1/4 inch tall.
She's been there for easily 10 years with no problems. There's an equally healthy Rita Sammons on one side, and a small-flowered, fragrant, bright pink foundling on the other. The foundling is lustier than Mae West, but prone to rust and downy mildew -- these don't deter her: for every cane that dies back, she sends out two or three in a most Gallica-like way.
Thoughts? Suspicions? Dark-of-the-moon hexes?