Why it’s Nopalxochia phyllanthoides ‘deutsche kaiserin’—one of Mrs. Samuel M. V. Hamilton’s favorite plants. (Mine too, although I don’t expect mine to look like this any time soon.)
This glorious plant, also called Cereus phyllanthoides, Epiphyllum phylanthoides, orchid cactus, or pond-lily cactus, was discovered in April 1801 in the trunks of old trees near the small village of Turbaco, a few leagues south of Carthagena.
It first flowered in Europe in May 1811 in the garden of the Empress Josephine and in another botanical garden in France. It became a popular parlor plant during Victorian times, probably because the winter weather encouraged it to bloom.
It takes cool temperatures to make this beauty bloom, but in the summer it can tolerate temperatures as high as 100F, as long as it doesn’t get direct sun.
Like all epiphytic (tree-dwelling) plants, it doesn’t like wet feet, although it does like to be kept fairly moist. Too much water makes the roots rot, as I found out the hard way. Take cuttings after the plant has bloomed, let them dry a bit, and root them in vermiculite or other medium that drains well.
There are other epiphytic cacti with knock-out blooms, some as large as your fist. Meadowbrook Farm has a number in its cactus greenhouse and will sell you a cutting, or even start you a plant. You can also learn more about these remarkable plants by joining the Philadelphia Cactus & Succulent Society or visiting its booth at the Flower Show.