I keep the majority of my plants at window sills, mainly the SW ones. The tropical sundews, many of the Utrics, and two types of pings all flower. Under the same conditions, other plants just have no inclination to flower: D. adelae, all Mexican butterworts, and a few Utrics. There have been many theories posited, such as the window pane, the age of the plants, natural difficulty of species, quality of light, dormancy/ slowing down period, etc... I was wondering how significant the day/night temperature differential is for the afore-mentioned plants, since the there is less occuring inside a room than there is outside?