S. White Knight is a cross between flava and alata and has bright white tops and flowers.
Here is a pic from my collection last summer.
"A hybrid of S. alata and S. leucophylla notable for the white upper pitchers uncharacteristic of this species cross." .. P. Sheridan
S. Lemon is a flava x alata hybrid. Pitchers are huge.
Here is a pic from meadowview. I don't have any personal pics of this one. Lemon is in reference to the bright lemon colored flowers it produces. Pitchers have heavy veining and are very pretty IMO.