poison

Poinsettia

The Mexican plant that has become a standard part of Christmas (and isn’t poisonous).

The poinsettia comes from Mexico & Guatemala and, in its untamed form, grows to be fairly gangly and around 10ft tall. Over the centuries it’s been selectively bred to be about 2ft tall with very dense foliage. The most well-known characteristic of the poinsettia is of course the bright red leaves along the top of the plant. These red leaves are not flowers but are the bracts of the poinsettia – specialized leaves that are different than the rest of the plant (the actual flowers, aka. the cyathia, are the small buds at the center of the red bracts). These special leaves are green until late autumn when, in the cooler shorter days, they turn red.

Poinsett to Poinsettia

The plant had already been known & used by the Aztecs for dyes and medicine but it came to the attention of the Western world through US Minister to Mexico (and amateur botanist) Joel Roberts Poinsett. Specimens had already been collected around 1803 by German scientific superstar Alexander von Humboldt, but it was re-discovered by Poinsett who introduced the plant to the US.

In 1828 Poinsett sent plants & seeds to Bartram’s Garden in Philadelphia (contrary to internet rumoring, there is no definitive proof that he sent poinsettia plants home to his native South Carolina). In 1835 Scottish horticulturalist and active member of the Philadelphia Horticultural Society Robert Buist named the plant the Euphorbia Poinsettia in honor of Poinsett. Buist also helped introduce the poinsettia to Europe.

Named for US Minister to Mexico Joel Roberts Poinsett, the poinsettia has been a standard part of Christmas for over a century.

Paul Ecke Ranch

Over the next century the poinsettia was cultivated into different varieties – shorter, taller, different colors, different patterns. The Paul Ecke Ranch of California have cultivated and sold poinsettias since the early 20th century. Having successfully produced cultivars which were more beautiful, more compact, and sturdier than other varieties, the Ecke family began to create and then dominate the market.

For decades they would send free poinsettias from November through December to a variety of media outlets. Ecke Rach poinsettias appeared on the Tonight Show, Bob Hope Christmas specials, the Dinah Shore Show, in magazines such as Ladies Home Journal and Better Homes & Gardens – all of which furthered the popularity and demand for poinsettias at Christmas. Today the Ecke Ranch (who were sold to the Agribio Group in 2012) is the largest poinsettia producer in the world with about a 50% share of the global market and around 70% of the domestic US market.

That Plant is … Safe

Poinsettias are not poisonous. While you or your pets probably shouldn’t eat the leaves of a poinsettia, you wouldn’t be struck dead if you did. The myth that they are deadly most likely goes back to 1919 when a child in Hawaii died of poisoning which was wrongly attributed to the poinsettia leaf. Research has shown that you would have to eat hundreds of leaves to produce mild irritation or vomiting at most. Given that the leaves are unpalatable and very bitter it’s unlikely you would eat enough to suffer the consequences.

Venomous vs Poisonous

Venomous species are aggressively toxic while poisonous species are defensively toxic.

The difference between venomous and poisonous is a difference of evolutionary strategies. It’s a difference of offense vs. defense, actively toxic vs. passively toxic.

Venomous

Venomous species use an active strategy to inflict toxins. As such they always have some sort of toxin delivery system such as fangs, barbs, stingers, spurs, etc. as a way to inject their venom. They are predators that use venom to incapacitate their prey.

Poisonous

Poisonous species defensively pass on their toxins when they are touched or eaten. This passive approach is why toxic plants are categorized as poisonous because, well, most plants don’t actively move around trying to attack prey.

As for poisonous animals the poison is frequently secreted through their skin as in the case of the poison dart frog (who got their name because their poison was sometimes used by indigenous tribes of Central/South America to make poisonous blow darts).

Poisonous species use their toxin to deter predation. Sometimes a predator only needs to be poisoned once to learn to never attack that poisonous species again. For others, a particular poison doesn’t leave the predator with the option of a second attack as the result is death.

In Short:

Venomous: when something toxic bites/touches you
Poisonous: when you bite/touch something that is toxic

Added info: While generally mutually exclusive, there are a few species that are both venomous and poisonous. One example is the Tiger Keelback snake of East Asia. It has fangs to inject toxin but more frequently it employs a defensive strategy and stores toxin in nuchal glands. Any predator that bites into the snake’s neck will be poisoned. The toxin they use for either strategy is not produced by the snake, but rather it’s acquired by eating poisonous toads.