This beauty is a beast.
Often sold in nurseries and garden centers as “dead man’s bells” or “witches’ gloves,” the common foxglove (Digitalis purpurea) is a popular addition to many landscapes.
Its pretty flowers come in various shades of pink, purple, white and yellow. Originally from Europe and North Africa, it can now be seen blooming in gardens all over the US.
But foxglove “can raise the dead and kill the living,” according to an old English saying. And it’s true: The foxglove can kill — though it also has lifesaving medicinal uses.
The secret is locked away in the leaves and flowers of the foxglove, which contain a compound called digoxin, a type of cardiac glycoside that has a powerful effect on the heart.
“Foxgloves contain extremely potent compounds called cardiac glycosides — ‘cardiac’ for their function on the heart muscle and ‘glycosides’ to indicate that these compounds have sugar molecules … to help the body absorb them,” Dr. Zhen Wang, assistant professor at the State University of New York at Buffalo, told Live Science.
But ingesting any digoxin causes problems within the heart that make it beat much harder and much faster almost immediately.
This sudden disruption to the heart’s rhythm, known as ventricular fibrillation, causes the heart muscles to quiver rapidly instead of contracting normally. This can lead to cardiac arrest and death, according to Johns Hopkins Medicine.
The digoxin in foxgloves — despite its lethal effects — is also an important and widely used heart medication. “Digoxin is clinically prescribed for heart failure when other drugs have failed,” Wang said.
“Heart failure is when the patient’s heart is so weak that it doesn’t pump sufficiently so you want to increase the heart’s pumping force. Although digoxin has serious side effects if overdosed, this is a special case where the benefit of the toxin outweighs the risk and could save the person’s life.”
The entire plant kingdom is filled with plants that can have sinister effects on human and animal health. Here are just a few.
Monkshood
Monkshood (Aconitum napellus), also known as the “devil’s helmet,” is much-loved for its tall, flowering spikes that bloom in summer.
But all parts of the monkshood are poisonous, especially the roots. If ingested, it can cause stomach pain and dizziness. The poison also affects the heart and can be fatal, according to the UK’s Woodland Trust.
And Aconitum plants have a nefarious legacy: The extract has been used to poison arrows, and in the Aleutian Islands in Alaska, harpoon tips are dipped in Aconitum to hunt whales.
Poison hemlock
A distant relative of the carrot, poison hemlock (Conium maculatum) has been spreading rapidly throughout the US and Europe.
The effects of the lavender-and-white weed, which resembles Queen Anne’s lace, can be felt even if you don’t directly touch it. An Ohio man had to be put on a ventilator — and into a medically induced coma —after inhaling some tiny particles of poison hemlock while clearing brush.
Deadly nightshade
Deadly nightshade (Atropa belladonna) lives up to its name. The plant has purple-green, bell-shaped flowers, oval leaves and berries that start off green and ripen to black.
All parts of the plant are toxic, but the berries are especially poisonous. They contain alkaloids that affect the nervous system such as atropine, which causes severe symptoms including sweating, vomiting, breathing difficulties, confusion, hallucinations and potential coma and death.
It also has a pupil-widening effect that was used as a beauty aid in ancient Greece. An extract of belladonna (“beautiful woman”) was used to make eye drops that were applied by women to dilate their pupils.
If you suspect someone may have been exposed to a toxic plant, do not try to induce vomiting, experts advise. Instead, contact a poison control center at 800-222-1222, or take them to an emergency room.
If possible, also take a sample of the plant for accurate identification, but be careful not to expose yourself to any toxins in the process.
