Short long day plants: these are long day plants but must be exposed to short day in early periods of growth for subsequent flowering. E.g.rye, wheat
Long short-day plants: these are short day plants but must be exposed to long day during early period for subsequent flowering e.g. Bryophyllum, night jasmine.
Intermediate plants (sterophotoperiods) : these plants can only flower within a definite range of light hours above and below where no blossoming occurs. E.g. some varieties of sugarcane
Amphiphotoperiodic plant: they behave just opposite to the intermediate plants where they remain vegetative in intermediate day length e.g. Mediaelgens.