Are nightshade plants such as Cestrum Nocturnum considered selenotropic?

what?

They make use of some of the surplus glucose they produced during daylight hours. All their growth, maturation & reproductive processes use glucose for energy, & as long as some of the day's production remains unused, the plant can carry on with business as usual. Of course, some processes are timed to take advantage of daylight, for example, blooming, but this is not always because they are energy-intensive. Sometimes it is because they need day-active insects to play a role such as in pollination. Often the final maturation of the flower is done at night so it will be ready for the morning.