"The Romans developed a sophisticated flower trade, complete with all the taxation, accounting, and logistical issues that accompany any commercial enterprise. They knew how to force flowers to bloom early by pumping steam or hot water past them. They attempted greenhouses with thin walls of mica and used wheeled carts to move plants in and out of the sun. And as soon as these artificial means of cultivating flowers developed, along came their critics, who saw the floral trade as a bit unnatural, given the way it used technology to stay out of step with the seasons. It makes me uncomfortable to see sunflowers for sale at Christmas, so far from their summer season, and I am not alone. The Roman playwright and philosopher Lucius Annaeus Seneca wrote this in the first century AD: “Do not men live contrary to Nature who crave roses in winter or seek to raise a spring flower like a lily by means of hot-water heaters and artificial changes of temperature?"