I've been seeing some wierd things on my plants lately, and it's bugging me. Cure my paranoia and say they're completely normal, please! Some recent changes: addition of a metal halide light, a few repottings, and a media change.
N. rafflesiana, newest leaf. This little brown smudge is right where the red, sunburned part of the leaf meets the unburned green part. Normal, right?
Under the leaves, especially the older ones, of N. rafflesiana:
N. rokko x spectabilis seems to have something similar
and finally, I've noticed some premature leaf yellowing on N. 'sabre.' This is the newest leaf. I read on Tony Paroubek's website that leaves yellow when they get too much light, but this seems unrealistic since all summer the leaves were fine and now, in the winter, they're yellowing.
Any ideas as to what causes these things?