I forgot to add that I do have a child plant of 'Cameroons', which is 'Cameroon Night'.
CN doesn't (to my eye, anyway) have the
watermark of 'Cameroons'; it does have the (obnoxious, for my taste) white midribs of 'Peacock Maiden', and it may have inherited some rust resistance from the tet conversion of the latter. (Rust resistance is hard to evaluate in this garden, since we don't get rust outbreaks every year. Thus far the plant seems to have shown some resistance, but that might be a relative thing, or pure luck in evading infection.)
There are things that I don't like about 'Cameroon Night', though (apart from the lack of a
watermark) : the white midribs, the spottiness (from water or dew), the shorter-than-registered scapes, the short bloom season (low budcount and branching - but that might be an artifact of shade), the lack of rebloom. When the blooms are good, though (no water spotting), I can almost even forgive it the white midribs. (I do have some seedlings from it... nothing spectacular, though, and not a
watermark to be seen.)
Since I am trash talking cultivars, allow me to express my frustration that seemingly a lot of modern
white or near-white tetraploid daylilies have some degree of rust susceptiblity - or at least, that is my perception. Lately I've been hunting for
white tets with some degree of rust resistance, with the result that I've been putting some older tet cultivars onto my Buy List. I've also purchased Tetra 'Lillian's Thin Ice', which I hope will have the resistance that the dip supposedly has (and that it opens as well as the images seem to show - cool nights being another issue here).
I do somehow
still have the diploid
white 'Tuscawilla Tranquility', which shows resistance here, and last year I added some Mike Huben near-white diploids, which I hope will also have some rust resistance.