For a time, the ancient Romans believed silk was wool that grew on trees. Growers sprayed water onto the trees, washing the white silky fibers from the leaves, then their wives spun the wool into thread and wove the thread into cloth. That cloth was the silk Roman nobles flocked to acquire.
India's candlewood was suited only to the tropics, not the northern temperate zone. Yet several of humanity's great civilizations happened to lie at this latitude, so candlewood was never widely introduced to Europe. Instead, the wax scale insect was introduced.
The males of this insect looked much like a moth, with a pair of wings, but it was actually a scale insect. It mainly parasitized ash trees and privet trees. The wax was secreted primarily by the larvae; people collected the secretions from the branches to make snow-white candles that were hard and entirely odorless. British Jesuit missionaries brought them to Europe in the seventeenth century, but they never became widespread. Whale oil instead became the fuel used to light streetlamps.
Hogwarts's floating candles were neither insect wax nor candlewood, but produced by a certain vegetable. It had already been there when Pomona first took over the greenhouse the day before. At first, she had no idea why the vegetable had been planted there, and simply cultivated it as usual, until she found the reason on a bookshelf in seventeenth-century Cassino.
Besides Hogwarts's candles, there was also a "waxy" Draught of Living Death—the drink of walking death. It was a powerful sleeping potion. Whoever drank it entered a deep sleep resembling death. Unlike Hell Potion, however, someone who drank the Draught of Living Death could walk, rather than lying motionless like Sleeping Beauty, obeying others' commands as though sleepwalking.
Pomona wanted to try letting the Fireseed Bush "drink"