Date: 1997 June 24
The genus Selenicereus includes species with possibly the largest flowers in the Cactaceae family. The two flowers pictured here were some 25-30cm in diameter, and opened on consecutive days. In the first picture, you can see at the back the bud of the second flower due to open the next day.
The flowers each last for only one night, and the species of Selenicereus have variously been called "Queen of the Night" (or indeed "King...", "Princess..." etc., or "Night-blooming Cereus".
Without their flowers, the plants cannot really be said to be attractive, consisting of thin climbing stems with aerial roots. They appreciate being planted out, and will then grow very large and bear many flowers. My plants are limited by being in pots, and have to be re-started from cuttings occasionally, and just get a few flowers each year.
I acquired this plant as Selenicereus macdonaldiae but I am reliably informed by Ulf Eliasson that it is a plant of the grandiflorus/pteranthus complex, and that macdonaldiae is quite different.