Describing a phase during which light promotes flowering. In one theory advanced to explain photoperiodism it is suggested that short-day plants are in the photophile phase during the day but at night they are in the photophobe (or skotophile) phase when light inhibits and darkness promotes flowering. The alternation between photophile and photophobe phases is seen as a type of *circadian rhythm
. If the period of daylight extends beyond the photophile phase into the photophobe phase, as would occur with a short-day plant on a long day, then flowering is inhibited.