In the United States, December 12 is National Poinsettia Day, a time to honor a plant that has become symbolic of the holiday season. And while not everyone’s a fan, it’s hard not to marvel at the species’ growing popularity. Poinsettias have come a long way since they were first brought to the U.S. by Joel Roberts Poinsett. Back then, they were celebrated for their brilliant red color. These days, poinsettia hybrids come in every shade of white, pink, orange and even blue.

MEXICAN ROOTS

While they are now commonplace in the U.S., poinsettias (Euphorbia pulcherrima) actually originated in Mexico. In their natural habitat, they thrive in the moist, humid environments of the tropical forest. Unlike today’s more compact varieties, however, native poinsettias tend to be sprawling and vine-like. And they often develop into small trees or shrubs. 

Wild poinsettia, Euphorbia pulcherrima

It’s not surprising that, due to their bright red color, poinsettias have played a part in Mexican Christmas celebrations since the mid 1600s. But in the U.S., they were virtually unheard of until the early 1800s. That is when Poinsett, the first U.S. ambassador to Mexico, stumbled upon some of the unusual red ‘flowers’ while stationed in the country.

HOW THEY GOT THE NAME POINSETTIA

Poinsett, in fact, was so struck by the remarkable species that he took cuttings and sent them home to his family in South Carolina. When he later returned to the States, he started propagating the plants on his own. In time, Poinsett began introducing his specimens to gardens and nurseries throughout America.

The fluorescent ‘Luv U Pink’

As their popularity grew, poinsettias became known as the ‘Mexican Fire Plant.’ Just as in Mexico, their scarlet, star-shaped leaves and winter blooms made them a natural addition to holiday households. The plant was eventually renamed poinsettia in honor of its discoverer.

THE LEAF IS THE FLOWER

Looks can be deceiving. Although they appear to be flowers, poinsettias’ petals are in fact modified leaves (called bracts). The actual flowers are the tiny cluster of yellow spheres in the plant’s center. In order to produce the colorful bracts, poinsettias require at least 12 hours of darkness followed by a period of bright sun. This is a long process undertaken by the grower.

The yellow spheres in the center are the flowers

During the 1800s, poinsettias were mainly a greenhouse curiosity. It wasn’t until the early 1900s that growers began experimenting with additional colors. Then in the 1960s, the introduction of more compact varieties led to mass production and marketing of the holiday ‘flowers.’

As a result, today you can now find poinsettias in every shade of red, pink, salmon, yellow, orange and white. There are even a growing number of marbled and striped varieties. And there are more than 100 new cultivars in development.

THE U.S. BOTANIC GARDEN COLLECTION

One of the best places to view the newest poinsettia hybrids is the U.S. Botanic Garden, located just off the grounds of the United States Capitol. Not only are there interesting specimens grouped by color in the entry foyer, but there are also native Mexican species on display in the garden’s tropical atrium.

But the real surprise awaits in the rear of the garden. There, in a sun-splashed hall adjoining the restrooms, around 50 unusual varieties are on display. These are part of the U.S. Botanic Garden’s own private collection. 

Following are some of the standouts from the 2018 exhibit.

‘Autumn Leaves’

‘Jingle Bells’

‘Ecke White’

 ‘Red Glitter’

‘Christmas Beauty Cinammon’

THE NEWEST POINSETTIA HYBRIDS

Traditional poinsettias are selections of Euphorbia pulcherrima. But a process patented in 2003 has allowed growers to cross Euphorbia pulcherrima with Euphorbia cornastra to create some spectacular hybrids. Many of these new varieties feature much smaller central flowers, placing the focus more on the colorful bracts. Below are some more great examples from the U.S. Botanic Garden’s collection.

‘Princettia Hot Pink’

‘Princettia Max White’

‘Luv U Pink’

‘Luv U Soft Pink’

HOW TO PICK A POINSETTIA

When shopping for a poinsettia, make sure to select a plant that has dark green foliage all the way to the soil line. And choose plants that have fully-colored bracts and no green around the bract edges. Green edges are a sign that the plant is older and won’t last as long.

Most importantly, never buy plants with yellowed leaves. This is a sure sign of plant stress.

Although the holiday species are bred to be compact, they can break easily. Check to make sure the foil sleeve is not holding up cracked branches. And always remove the sleeve after purchasing. The plants need plenty of air circulation to survive.

Finally, water your plant well and allow it to dry out before re-watering. And avoid fertilizer, which will hasten the decline of the colored bracts. Remember to give your poinsettia plenty of sunlight to help it maintain its bright color.

TOXICITY

You may have heard that poinsettias contain toxins, And it’s true that the sap and latex of the leaves can sometimes cause an allergic reaction. That said, the plants themselves are not poisonous. As for the commonly-held belief that the plants are toxic to pets, the Pet Poison Helpline confirms that while poinsettias are listed as toxic to dogs and cats, they are only mildly irritating to the mouth and stomach if swallowed.

THE RIGHT WAY TO PRONOUNCE POINSETTIA

Poinsettia is traditionally capitalized since it is named after a person. According to the Oxford Dictionary, it is pronounced poin-set-ee-ah.