I bought this N. ventricosa a few years ago, and I grow it in a pot set in a 10 gallon fish aquarium that has an open top, but I largely cover the opening with plastic wrap to raise the humidity. There are 3 plants of N. ventricosa in the aquarium -- the plant shown here, plus two offspring.

All has been going reasonably well, but I see that the last two traps of the original plant have a very stunted and deformed cover-leaf for the pitchers. The pitchers themselves seem very healthy, it's just the leaf that covers the pitchers that is deformed (shrivelled and black, never developed properly). The two offspring plants in the same aquarium do not have this problem, their pitchers and the pitcher cover-leaves seem perfectly normal.

Anyone come across this before? What's the problem? What's the solution?... Thanks,

Don

General view of plant:

{{gwi:552023}}

Focus on a pitcher with a deformed cover leaf. This is the newest pitcher on the plant.

{{gwi:552024}}