White baneberry
These berries contain cardiogenic toxins that serve as a sedative on cardiac muscle tissue. Immediate symptoms include burning of the mouth and throat, salivation, severe stomach cramps, headache, diarrhea, dizziness and hallucinations. Hmmmm. I'll pass.
Interestingly enough, they got their alternative name, Doll's Eyes from once being sewn into rag dolls for children as....you guessed it...doll's eyes. Weird. Actually, the berries look a lot like Hatchimal eyes to me. And if you don't know what a Hatchimal is then consider yourself quite lucky.
Yews
And that's because the murderers always had such easy access to the poison taxin through this classic evergreen that is a staple around many homes in England. It is the go-to hedge for looks and luxury, not to mention death. Quick recap: Flesh of the berries, okay. Seeds and leaves, highly toxic. Even still, it's not like I'd be throwing the flesh of these berries in my smoothie any time soon.
Interesting fact. Sometimes, there's no symptoms at all. Other times (such as in my murder mystery novel) the victims heart rate starts accelerating, then they experience muscle spams and labored breathing as they dramatically stagger and finally collapse to the floor.
And the yew is poisonous to almost all including humans, dogs, cats, horses, cattle and pigs.
Yew is also one of those rare plants where the poison is not destroyed when the plant dies. So when you move those branches via pruning or they move themselves via high winds, bad things are sure to follow.
Rhododendrons
Okay, then, the good news. There are few, if any known incidents of fatal poisoning in humans in recent times involving a rhododendron plant. Even though this plant is poisonous to many animals as well, cases are rare because animals tend not be graze where rhododendrons are grown. Sadly, they get poisoned when unthinking humans feed, for example, zoo animals the plant growing on the zoo grounds. Not smart on the humans part but maybe the zoo shouldn't have chosen different decorative plants.
The bad news?! All parts of the plant including the leaves, flowers and the nectar contain toxins with the nectar usually believed to have the highest concentration. Humans poison themselves when when they eat honey made with rhododendron nectar. Why anyone would do this is beyond me.
But those who do poison themselves in this way typically see their gastrointestinal and cardiac problems disappear after about 24 hours. It obviously depends on the amount of nectar consumed. Those unpleasant symptoms include low blood pressure, lowered heart rate and shock, nausea, increased salivation and vomiting, accompanied by dizziness, loss of balance and difficultly breathing. Sounds a lot like a pharmaceutical ad to me.
Short recap. Lavender tea with honey. Yes. Rhododendron tea with honey. No. Never. Still the plant is stunningly gorgeous, just don't ingest.
Castor bean
Anyhow, ricin is very poisonous to humans, animals and even insects. Rumor is that as few as 5 beans is enough to kill an adult human, but I have not tested this myself and don't plan too.
Castor oil is produced by pressing ripe seeds that have had their outer covering, also known as a hull removed. It's this hull that contains the deadly ricin. Castor oil has been used as a medicine for centuries, this brings to mind the Mary Poppins song where the little boy sings about not wanting castor oil or gruel from his prospective nanny. I'm with him! There are much better laxatives and wart removers out there, I'm sure of it.
Monkshood
And yes, if you ingest this plant, even just a smidgen will cause severe and unpleasant gastrointestinal upset, but it's the heart that takes the greatest toll. It will quickly slow the heart rate and this is the main cause of death. Early symptoms include restlessness and excessive drooling followed by muscle weakness, falling blood pressure and difficulty breathing
Fortunately, its bitter taste is awful and is quickly followed by a burning sensation, numbing of the mouth and all those other icky side effects. BIooms may be gorgeous but it's unwelcome in my yard as I have small children and pets. Let's just avoid this one....okay? It's like I tell my 5-year-old every day, "look but don't touch mommy's glass trinkets from Holland."
Fun factoid? Monkshood was once used by ancient warriors to poison the water of their enemies!
Bittersweet nightshade
They begin as a green berry, then they change to yellow, orange and finally red when mature. The plant is even more striking when you see one in multiple stages sporting colors in each of these hues at the same time. They certainly look delectable, especially growing alongside blackberries, but they're not. So if you have bittersweet nightshade growing in your yard, you'll want to remove it using gloves as the foliage is toxic not to mention prickly.
I've witnessed lots of birds nibbling on these berries and you probably have as well if you like to hike. Because the seeds are able to pass through the digestive tracts of many animals including those birds and remain viable, they are spread like wildfire to new locations, enabling this plant (weed) to spread.
Angel's trumpet
Because there's no gray area with the lovely Angel's Trumpet plant with flowers that hang like bells. It's all bad, every last bit of this woody-stemmed bush including the flowers, leaves, seeds and roots are poisonous to both humans and animals.
This plant contains toxic alkaloids that cause poisoning when ingested or absorbed through mucus membranes. So don't eat it or let it come anywhere near your skin! Side effects include agitation, twitching movement, muscle weakness, drowsiness, dilated pupils, dry mouth, rapid pulse, fever, hallucinations & euphoria and elevated temperature. Don't rule out coma or death either when up against the evil Angel's Trumpet.
Besides, this high-maintenance plant likes routine pruning, feeding and watering. You'd have to wear protective clothing, gloves and probably goggles to consider working with it. Even the pruning sheers you've used on this plant would then have to be thoroughly washed when finished. Left unwashed, the pruners could actually contaminate your other flowers or worse, your vegetable plants. It's possible for even gloved hands to get contaminated and for you to be unaware of this. When the gloves come off, just the act of rubbing your eyes or touching your face might send you to the emergency room when the rapid onset of symptoms appear.
It's even possible for the Angel's Trumpet to harm through cross-contamination with your edible crops so it can't be anywhere near your vegetable bed or herb garden.
Delphiniums
I had no idea that just touching these tempting buds can irritate the skin. Children in particular are drawn to their vibrant beauty and almost can't help picking them, but contact with the skin is dangerous. Is this why children's authors use the lovely larkspur on note cards for kids and in children's gardening books? Not a good idea!
Rumor has it that it has a bitter and acrid taste, but if you push past that issue and continue to munch, you could actually die from its potent alkaloids. Initially, you'll feel disoriented with muscle tremors, stiffness, weakness and finally keel over from respiratory paralysis. And don't rule out paralysis or even death as both are possible.
I found it fascinating that larkspur has been used in the past in some herbal medicines such as anti-parasitics (they go after lice), a cure for asthma and maybe even as a preventative for eye disease.
White snakeroot
Guess what's even more odd? It's possible still today to get sick off milk contaminated by snakeroot if the cows made that same mistake. Of course, you might get sick and have no idea it was some milk you drank that put you over, let alone milk contaminated by snakeroot. Crazy!
And not to be captain obvious, but obviously eating the plant straight-up can easily lead to death. The symptoms are too numerous to even list, just avoid!
Foxglove
Why'd you consider sucking on the flower is beyond me, but if you do other symptoms include digestive issues, headache, blurred vision and overall confusion. Besides, there are plenty of other edible flowers to choose from, why go with one that will kill you?