Every once in a while I will have a Nepenthes, usually a 4"-6" diameter plant, that has been established for many months suddenly blacken at the stem, and or growing tendril. Then the leaves start to wilt and blacken and then the plant dies. On a rare occasion the dying plant will send out a sideshoot but often it is too late and the plant dies. What's also unusual is the moss or growing medium doesn't stink or have any "slime" in it. The plant shows no symptoms until one day you notice "hmm....that guy is wilting" and then proceeds to kick it.
I know I've had plants that were sitting in water or kept way too wet rot out. But this occurred with a rajah that was outdoors for over a year! When I checked the root mass, there were plenty of roots and the plant "appeared" fine. From my experience, it's usually the growing tip the turns black first and then the rest of the plant follows suit and dies. This was the reverse. It started on the lower leaves. Any ideas out there?