Euphorbia pulcherrima

Chance are, you read that botanical name and didn't realize it was the name for what may be one of the most recognizable plants in the country, poinsettia.  The specimens below are growing next to a fairly recognizable man, George Washington.  These shots were taken at the National Cathedral. 

 

Poinsettias are named for Joel Roberts Poinsett, the first US minister to Mexico.  The plant is native to Mexico, though can be found in some other parts of Central America.  Its association to Christmas began in the 16th Century in Mexico, when folklore began to tell of a young woman who was too poor to offer gifts to the church. She gathered weeds, presented them to the altar, and the next day they became brilliantly red flowers.  

Of course, here comes the part where I ruin some of the fantasy of the story.  The red "petals" one associates with a poinsettia flower are merely bracts.  The small yellow and red bundles above are the actual flowers.  Bracts are modified leaves and in the case with this species, they turn red only after they consistently receive twelve hours of darkness each night.  This is called photoperiodism.  The red (or white, pink or marbled hues) are brightest however if the daylight is as bright as possible.  Of course, nearer to the equator, this light requirement is easily achievable all year long.

In Mexico, the plant is commonly referred to as "noche buena" which is also a term for Christmas Eve.  Given this, it seemed like an appropriate plant for today's post.  Merry Christmas!