Joel Poinsett, the 1st US Ambassador to Mexico, found the plant growing in Mexico and brought it back to the United States. It’s scientific name is Euphorbia pulcherrima (meaning very beautiful euphorbia). William Prescott, a horticulturist, renamed the plant poinsettia in honor of Joel Poinsett.
Starting in 1900, the Ecke Family of California became the leading producers of poinsettias

Simple Facts:
Poinsettias are not poisonous
The sap of poinsettias may cause skin irritations
In nature poinsettias are perennials
The showy colorful part of the plant is really modified leaves (bracts)
The flowers are the tiny things at the center of the bracts
Poinsettias are the best selling potted flower on the United States.
85% of flowers sold at Christmas are poinsettias.
Selecting a Poinsettia
Should have dark green foliage down to the soil line
Bracts should be completely colored
Colors available today: red, pink, white, salmon, jingle bell, burgundy, marble, peppermint, Da
Vinci, Monet, with new colors added every year
Plant should be full and balanced on all sides
Do not purchase plants that are still in their paper or plastic sleeve
Do not purchase plants that are pushed together on over crowded shelves
Do not purchase plants that have yellow pollen on their leaves (plants are past their prime)
Care of Poinsettias
Protect from cold and wet weather when you take them home, both of theses cause leaf damage
Keep them in a cool room with indirect light and they will last longer
Water when dry, over watering will cause leaves to drop off as will excessive under watering
Do not fertilize while in bloom
Getting a Poinsettia to Reflower
THIS IS NOT EASY!
In February or early March cut the plant back to 4″-6″ above soil line
Late spring or early fall repot into container 2″-3″ larger than original
Keep pinching leaves to encourage branching
Flowering is photo periodically; it happens when nights are long
Without long periods (at least 12 hours) of totally darkness, flowers will not form
It takes 60-85 days of this darkness for flowers to set
Once color starts to show remove from dark area