Oddly one of the four that I cut back yesterday had that black color and it was really odd. It also seemed to ooze a LOT more then the other 3, I had to go back and use alcohol to remove the black that dripped down the main stem. There are near black marks on the paper towel I wiped the blade down with, I was laying each cutting on them and labeling them so I could keep track of which was from which plant. I will try and root these this time but I'll make a note which one had the black and see if there's any difference later on.
