Which planes have no horizontal stabilizer?
Which planes have no horizontal stabilizer? A tailless aeroplane has no separate horizontal stabilizer.
Why do horizontal stabilizers not have winglets?
Putting them on the tail surface would not help to limit the wingspan: The horizontal tail can easily grow and still be much smaller than the wing. There is no single case where winglets on a horizontal tail would have made sense. What you see and might interpret as winglets are actually additional fins.