Yes, I think you are right. I had that happen once when I had a clump that I thought had died and I dug it out and planted a different species. Apparently I didn't get all the rhizomes out for the first bamboo and those roots were not completely dead. Several years later I had two different species hopelessly intertwined.

Thanks for the reply. I had planted some (a friend dug up from his yard) the year prior that died. I just hope that the green shoots are not running bamboo.

Do the green culms have more than two branches at the nodes? If so, it's a clumper.

I got home late and took the kids in bike ride so I didn't have a chance to look and take a pic during the daylight. If this is what you mean by more than two branches at the nodes, then it's a clumper. 😀

Given the appearance of the culm and its branching pattern, I'm about 98% certain that's another clumper intermingled with your Alphonse Karr, maybe one of the many other Bambusa species. To get another opinion -- hopefully confirming -- go to the Bambooweb web site and post the same info on their Bamboo ID forum: Bamboo ID

That is very encouraging. I will make a post on that forum to confirm. Thanks

Good luck. That’s the best site for bamboo ID and photos. Please report back on what you find out.