So, peculiar question here, but the lady I bought mine from knows nothing about plants, she just sells them... I have a nice pot of a black bamboo. The most interesting thing to me, though, is that this one changes colour from green to black within months. The new culms I've gotten this year, not even fully flushed yet, still growing, are starting to get speckled already, only a couple of weeks old. The culms from last October / November are completely black. Is this a distinctive characteristic of any species you know, or has another mutant found me?
It's been years since I grew P. nigra, but I seem to remember seeing this general effect -- perhaps not as dramatically as you are seeing -- even with the ordinary species. I remember wondering at the time whether the color might not fully develop until the young stems were exposed to sunlight.
My run of the mill Ph. Nigra did the same thing, seems to be a factor of how much sunlight they are exposed to. I know the standard info you see gives the impression that only big mature culms turn black but I think that's false.
