The domestication of the poinsettia
If you saw a poinsettia out in the wild, there would be vast differences from the commercially-bred ones you see in storefronts around Christmas time.
The wild poinsettias grow around 15 feet tall and are a single stemmed shrub with smaller bracts being about an inch wide and four inches long. Commercial poinsettias have bracts that are three to four inches wide and four to six inches long.
“The domestication process has created a plant that is a lot more showy and compact and able to be produced commercially in large numbers in containers,” said James Faust, floriculturist and associate professor at Clemson University. “It’s really a totally different plant, except for the flower, you wouldn’t recognize it.”
The plant was introduced to the United States when the first American ambassador to Mexico, Joel Roberts Poinsett, sent the plant home to his greenhouses in Greenville, South Carolina.
“Poinsett was a horticulturist and was really interested in how plants might be used to help the economy develop, so he kind of facilitated the shipment of plants between Mexico and the United States that had potential commercial value. So, he’s sending food crops that he’s seeing in Mexico, things like avocados, and he’s sending seeds up from Mexico while he’s the first ambassador,” Faust said.
Yet the plant that Poinsett introduced to the United States, Faust suspects, was not wild. It had already been domesticated by the Aztecs, who selected plants from the wild and grew them in their landscapes. The Aztecs were in fact the first to have botanical gardens and domesticated other flower crops like marigolds, zinnias and dahlias.
“We don’t have direct evidence that they domesticated the poinsettia, but they were certainly used in the landscape and had already been collected out of the wild when the Europeans had first arrived,” he said.
The Aztecs’ botanical gardens cultivated plants for medicinal purposes, and the people used the poinsettia as a source of purple dye and as medicine for fevers.
“My suspicion is that when you look at the drawings of the first plants Poinsett brought back, they don’t look like the wild ones,” Faust said. “They look more like a domesticated poinsettia and that the bracts were much larger, but that’s why I think the plants were already domesticated to some extent. Now it’s still not anything close to a commercial poinsettia today, but it was certainly a lot showier than the wild ones.”