When people think plants, they are likely thinking flowers, vegetables, fruit trees, flowering trees, shrubs, etc. But going forward, also consider the leaves!

I picked up this Alice Thoms Vitale book years ago—because that’s the sort of thing I do—and I must admit that I set it aside for quite a while. Big mistake! It’s fascinating.

Here, for your entertainment and enlightenment, are samples and quotes from that book. All such are from Leaves unless otherwise noted.

Virginia Creeper

It’s native and ubiquitous and, besides creeping, it trails and climbs. I work hard to keep it from overpowering nearby plants in my back yard. Nevertheless, in late autumn, the leaves turn deep scarlet, one of the few spots of color then.

They played an important role in American folk medicine as an emetic, purgative, and sweat producer. Not surprisingly, they taste bad. According to Vitale, some people also considered them mildly stimulating. To cure a headache, people smelled the juice of the leaves, or took an infusion of the leaves and berries. It had other medicinal uses as well. And, “An old belief claimed that a strong tea of Virginia creeper leaves healed even the worst hangover.” Maybe it will come back!

Vitale saw vendors selling it in pots as “American Vine” under the Rialto Bridge in Venice. If I saw it there, I didn’t recognize it.


Although Vitale discusses English Ivy, it grows robustly—some would say invasively—here, so read on.

This evergreen vine has been central to magic, mythology, and medicine at least as far back as the ancient Greeks. Looking only at medicinal uses, Vitale lists twenty such uses, everything from bad spleen and baldness to ulcers and wounds.

“It is now scientifically established that all parts of the ivy plant are poisonous if ingested …can cause … illness—even death.” On the other hand, researchers in Romania have recently established ivy’s effectiveness as an antibiotic and antifungal treatment.

Apple Trees

Most people know apple trees primarily for their beauty and fruit; the leaves, not so much. The Greek physician Dioscorides said, “The leaves and blossoms and sprigs of all sorts of apple trees are binding.” Centuries later, an English herbalist said, “The leaves of the tree do coole and binde, and also good for inflammations in the beginning.”

Vitale’s book says no more about apple leaf medicine, but online I read that apple leaves have cooling and astringent properties. Some people use them therapeutically for stomach acid issues – heart burn, reflux, and all the way down to soothing digestive issues of the bowel such as diarrhea.

Various parts of the apple tree have many applications, and are widely used in oriental medicine. For the leaves in particular:

  • In China, doctors use the leaves to treat fever, back pain, amenorrhea, and migraine.
  • In India, the leaves of the apple tree are a common prescription against malaria, diarrhea, and rheumatism.
  • In Vietnam, some people steep apple tree leaves in the bath water of women who have recently given birth.

Currently, experts have discovered that the apple tree contains compounds that help fight HIV, which is a good signal in the search and preparation of drugs to treat this century’s disease. In addition, the extracts from the leaves of the apple tree have anti-fungal effects on skin diseases, inhibit the vascular donor activity associated with a number of diseases such as diabetic retinopathy, arthritis, solid tumors…

And we can’t forget the famous Johnny Appleseed (aka John Chapman) who carried apple seeds from a cider press in Pennsylvania across the country. While traveling the Ohio River Valley, he planted more than 35 apple orchards in Ohio, Indiana, and Illinois.

Beware: apple seeds contain cyanide, and eating a cupful of them can cause cyanide poisoning. But who would do that?


Vitale writes quite a bit about European mistletoe. But my focus is on American mistletoe, so what follows is from sources across the web. The two differ primarily in the shape of the leaves and the number of berries in the clusters.

American mistletoe grows only in the Americas, from New Jersey to Florida and west through Texas. Most people know it best for its ornamental and sentimental uses at Christmastime.

As for kissing under the mistletoe, that seems to have immigrated from Europe. In Norse legend, the trickster god Loki played a sinister trick on the beloved god Baldur, killing him with a mistletoe arrow. After his death, mistletoe berries somehow brought Baldur back to life, so Frigga declared mistletoe to be a symbol of love. According to Smithsonian magazine, “Mistletoe would come to hang over our doors as a reminder to never forget. We kiss beneath it to remember what Baldur’s wife and mother forgot.”

American mistletoe (Phoradendron leucarpum), also called eastern or oak mistletoe, is a parasitic shrub that grows on the branches and trunks of trees across Virginia. It grows most commonly on oaks, red maples, and gum trees and is most abundant in the swampy forests of Virginia’s Coastal Plain.

Both American and European mistletoe can be toxic in high doses, but neither has been convincingly shown to cause clinically apparent liver injury when given in conventional doses.

NIH — LiverTox: Clinical and Research Information on Drug-Induced Liver Injury

American mistletoe was once used to counteract fertility. Native Americans employed the muscle-contracting medicinal properties of the plant to induce abortions.

The Biology of Mistletoe, Smithsonian Magazine

Woody Nightshade

The nightshade family is one of the largest plant families and is related to potatoes, tomatoes, peppers, and eggplants, among others. However, plant lovers also know woody nightshade as deadly nightshade or poisonous nightshade because all parts of the woody nightshade are dangerously toxic if eaten raw. Nevertheless, the leaves and green branches have historically played an important role in folk medicine.

In the second century, Galen (a Greek physician) recommended its use for treating cancer, tumors, and warts. According to Vitale, “…recent scientific studies prove that this plant does indeed contain a tumor-inhibiting element.”

Other authorities over the centuries have recommended the juice of the leaves for treating those who have been beaten or bruised, shingles, “hot inflammations,” and chronic rheumatism.

Mashed leaves in cream was recommended as a poultice for poison ivy and to treat sunburn. Modern chemists have found that this nightshade does contain solanine, “…a substance effective for healing obstinate skin disorders and ulcers.”

And if that isn’t enough, this plant is reputed to have healing magic!


Flowering oleanders—whether the clusters of blooms are pink, rose-red, or white—are gorgeous. They have a variety of scents—vanilla, lemon, apricot, and floral with a hint of spices—depending on species, time of day, and developmental stage.

Warning: all parts of the shrub are poison. Eating a single leaf or eating meat cooked on a skewer of oleander wood can be deadly. In India, it’s called “horse killer” but it is lethal for dogs, mules, and many other animals.

At the same time, historically, people treated venomous bites by drinking the juice of oleander leaves with wine. The juice relieves scabies, mange, and abscesses. It’s also useful as a pesticide and rat poison. Modern researchers have developed a treatment for weak heartbeats from oleandrin, a glycoside in oleander.

Lemon Verbena

Although many (most?) leaves are some combination of pros and cons, plusses and minuses, lemon verbena is all about loving it.

Wherever lemon verbena grows, the leaves perfume the air around. The dried leaves retain their scent for years, hence their popularity for potpourri and sachets.

Lemon verbena oil is a frequent ingredient in perfume, and in other cosmetics and creams.

The leaves haven’t contributed much to medicinal uses. However, decoctions have been taken as a sedative and for indigestion.

Tea made from lemon verbena leaves is widely popular for the flavor alone (for example, in Brazil). In southern Italy, women wishing to get pregnant often drink such tea—although there is no science supporting that tea as a fertility aid.

Bottom Line: Leaves are often useful as well as ornamental! Whether you take a leaf or leave it depends on your goal—and risk tolerance!


“Why hellebores?” Well might you ask. Because they are my favorite! And because they can be useful for your characters and plots.

When we moved to Ashland, Virginia, we bought an 1858 Greek Revival house on a double lot with old trees and daffodils and not much else. I searched for shade-loving, blooming, evergreen, low-maintenance plants. Voila! Hellebores. They are all of that plus, as a bonus, the blooming happens in winter and early spring.

Behold Hellebore niger, aka Christmas rose, a welcome sight come December. It’s pretty and reliable! The opening picture is from this year, New Year’s Eve. The picture just above is from 12/21/18.  Hellebore niger is the earliest blooming hellebore I’ve found.

Close on the heels of the Christmas rose is the Lenten rose (aka Hellebore orientalis) and its various hybrids. Please note: despite being called Christmas rose and Lenten rose, hellebores are only distantly related to the rose family. This picture of purple and double white hellebores is from March 3, 2019.

Although the flowers and foliage of most hellebores are similar, the Stinking hellebore (Hellebore foetidae) is distinctively different. Its leaves are narrow and knife-like, and cluster at the ends of stalks. The flowers are smaller and droopy, and mostly a pale green.

Hellebores bloom throughout the spring, in a riot of colors. They bloom until the heat of June or July do them in. At that point they drop seeds, and where they are happy, they spread into lovely clumps.

Although they need water during droughts, they are low maintenance. Prune browned-off leaves and dry flowers at will. There are supposed to be a couple of insects and a fungus or so that can attack them, but I’ve never had either. Animals—deer, rabbits, etc.—usually don’t chomp on hellebores because of the (dis)taste of the leaves.

So no wonder I (as well as real gardeners) love hellebores!  But why would a writer care?

All parts of all hellebores are toxic! 

Smart rabbits eat only non-toxic plants in your garden!

Somehow, this did not come to my attention when I wrote My Poison Garden last fall. (How could that have happened?)

Although poisoning is rare, it does occur through ingestion of large quantities, and it can be fatal.

  • Symptoms can include any of the following 
    • Burning of the mouth and throat
    • Excess salivation
    • Vomiting
    • Abdominal cramping
    • Diarrhea
    • Nerve system dysfunction
    • Possibly even depression!
  • The roots contain cardiac glycosides.
  • Leaves and sap contain high levels of ranunculin and protoanemonin.

How might a character be induced to ingest large quantities of a foul tasting plant? 

All you can eat ranunculin and protoanemonin!

Dermatitis is fairly common, caused by handling the plants without protection.  Contact with leaves, stems, flowers, and sap can cause irritation and burning on the skin. Minimal exposure should cause a mild, short-lived irritation and can be treated by washing with soap and water. How might a scene be affected by a character suffering contact dermatitis?

This is a hellebore that is black, not a Black hellebore.

Although hybrids that look nearly black have been developed, historically Black hellebore is another name for Hellebore niger, the white blooming Christmas rose. Black hellebore was used by the the ancient Greeks and Romans to treat paralysis, gout, insanity, and other diseases.  Beware: it can also cause tinnitus, vertigo, stupor, thirst, difficulty breathing, vomiting, catharsis, slowing of the heart rate, including collapse and death from cardiac arrest. Not quite so serious: can cause burning of the eyes, mouth, and throat; or oral ulceration, gastroenteritis, a hematemesis. Could the toxicity of hellebores create an illusion of a chronic disease or disorder of unknown origin?

Folklore and legend vary from the sacred to the dark arts. Could your plot take elements from these?

  • According to legend, a young girl who had no gift to give the Christ child in Bethlehem wept, and her tears falling into the snow sprouted the Christmas rose.
  • Witches are reputed to use hellebores in summoning demons.
  • Heracles/ Hercules killed his children in a fit of madness but was cured by using hellebore.
  • Greek besiegers of Kirrha (585 BC) used hellebore to poison the city’s water supply, overcoming the defenders weakened by diarrhea.

Bottom line for gardeners and writers: get thee hellebores!

Poisonous flowers make lovely Christmas cards!


Xylaria Polymorpha (Dead Man’s Fingers) aren’t actually poisonous, but they look like perfect fertilizer for deadly flora!

This summer, I noticed a volunteer growing among my hellebores. I identified it as Carolina Horsenettle (Solanum carolinense), a member of the nightshade family. It looks like a nettle because of the small spines on the stems and leaves. Fortunately, I was able to dig it out before it matured, but what I read said it blooms from April to October and that the crushed leaves smell like potatoes. It produces deceptively pretty, little, white flowers.

Horsenettle grows in pastures, along roadsides, in disturbed areas, and other types of “waste” ground. It can tolerate both wet and dry conditions—i.e., practically anywhere. Symptoms of horsenettle poisoning include nausea, vomiting, excess salivation, drowsiness, diarrhea, and weakness. Although horsenettle poisoning is seldom fatal, ingesting the fruit can cause abdominal pain, circulatory and respiratory depression, and occasionally death. Fatalities are most common among children.

Horsenettle produces fruits that look like very small tomatoes, starting out green and turning yellow. In order of toxicity: unripe berries, ripe berries, leaves, stems. Toxicity is stronger in autumn.
So, I wondered: what other plants, growing innocently in gardens, might meet the needs of poisoners.  I just happen to have on my shelf the perfect reference for this subject—Book of Poisons: A Guide for Writers. It is part of the Howdunit series, books providing technical information for writers of crime and mystery books. According to Stevens and Bannon, plants are the source most accessible to the average poisoner.

The authors organized plants into groups:

  • Plants that are quickly fatal, like foxglove
  • Plants that can be mistaken for edible, like castor bean
  • Plants eaten by animals whose meat is then poisonous for humans, like laurel
  • Plants that are edible in small quantities, like ackee berry
  • Plants that have certain edible parts, like rhubarb
  • Plants that are edible during certain times of the year, like mandrake
  • Plants used for medicinal purposes, such as ergot
  • Plants that flower, like rhododendron or azalea
Rhododendron from New River Gorge

Stevens and Bannon rated all of the poisons for toxicity—not just the plant-based ones—according to the amount required to kill a person. Weight and metabolism vary, and the authors provide a means of extrapolating the fatal dosage for a person of any size or circumstance. Here’s a quick and dirty list for writers, based on a vaguely average 150 pound human being:

  • 6—Supertoxic
    • A taste, less than 7 drops
  • 5—Extremely toxic
    • Between 7 drops and 1 teaspoon
  • 4—Very toxic
    • Between 1 teaspoon and 1 ounce
  • 3—Moderately toxic
    • Between 1 ounce and l pint or pound
  • 2—Slightly toxic
    • Between 1 pint and l quart
  • 1—Almost nontoxic
    • More than 1 quart or 2.2 pounds

Given that my poison garden is in Virginia, I looked for poisonous plants of Virginia, and found that Virginia Tech has compiled such a list. (FYI: if your poison garden is elsewhere, search online for an equivalent collection for your area. For example, I know there are such lists for West Virginia and Ohio, as well as guides for all states and all regions.) So here, in alphabetical order, are the plants in my poison garden. I’ve omitted plant descriptions and locations in favor of what part(s) of the pant are toxic and the symptoms. Greater detail is readily available if one of these little beauties appeals to you.

American False-hellebore (Veratrum viride), aka Indian Poke, has a toxicity of 5. All parts of the plant are poisonous and potentially fatal when ingested by humans or livestock. Don’t touch or handle any of it with bare hands, because the toxic compounds can be absorbed through the skin. Symptoms of False Hellebore poisoning include nausea, vomiting, abdominal pain, dizziness, seizures, decreased blood pressure, slowed heart rate, heart arrhythmia, coma and, potentially, death. On the other hand,Veratrum viride can have medicinal uses as pain reliever, heart sedative, and to lower blood pressure.

Giant Hogweed (Heracleum mantegazzianum) is not a native plant, but it has been found in isolated parts of Virginia as well as Maryland, North Carolina, and Washington, DC. Although not typically poisonous, it’s very dangerous to humans and shouldn’t be touched at all. The sap is strongly toxic for humans, resulting in serious skin reactions after exposure to sunlight. Eventually, this skin rash changes to blisters that look like burn wounds. A red-purple scar may develop that can last years. Exposure of the eyes to plant juice may lead to blindness.

Jimson-weed (Datura stramonium), aka Jamestown weed, has a toxicity rating of 6. Although also not native to Virginia, it grows everywhere: in pastures, fields, waste areas, and in sand and gravel bars near streams. All parts are poisonous. Sometimes seeds are ingested directly, or plant parts brewed brewed into tea. Exposure often results in hospitalization. In small doses, it is hallucinogenic. Besides hallucinations, symptoms include headache, delirium, agitation, large pupils, constipation, urinary retention, elevated pulse, hypertension, and fever. Stevens and Bannon said, “Accidental poisoning is most often caused by the seeds […] Both adults and children have been fatally poisoned by tea brewed from the leaves or seeds of this plant.”

Mayapple (Podophyllium peltatum) aka Wild Mandrake, is most likely found in forests—but it’s in my poison garden, and I’ll include it! Leaves, roots, stems, seeds, and unripe fruit are toxic. Symptoms when ingested include nausea, vomiting, diarrhea, and abdominal pain, followed by organ failure, coma, and potentially death days later. Ripe fruit is edible, but mistakenly eaten not-quite-ripe fruit leads to all of the above.

Poison Hemlock (Conium maculatum) is a member of the carrot family… but grows 6 to 10 feet tall! It has a toxicity rating of 6. It’s an invasive non-native. All parts are extremely poisonous, the blooms emit a foul odor, and the leaves acts like nicotine. Juice from Poison Hemlock can cause severe skin irritation. Internal poisoning often occurs after a victim confuses the root with wild parsnips, the leaves with parsley, or the seeds with anise. Hemlock tastes similar to lettuce. Whistles made from the hollow stems have been reported to lead to death in children. Symptoms include nausea, vomiting, diarrhea, abdominal pain, coughing, wheezing, watery eyes, salivation, sweating, difficulty seeing, weakness, dizziness, trembling, seizures, paralysis, changes in pulse rate, coma, and potentially death.

Pokeweed (Phytolacca americana), aka Pokesalad, is found pretty much everywhere: fields, fencerows, roadsides, crop fields, and forest edges. It has a toxicity rating of 4. All parts of the plant are seriously poisonous. The juice can be absorbed through the skin, causing itchy skin and/or painful rash. Symptoms of ingestion include nausea, severe vomiting, abdominal cramps, diarrhea, burning sensation in the mouth, visual impairment, weakened respiration and pulse. Dehydration caused by these symptoms can be severe enough to lead to convulsions and death. People have tried to cook the leaves with spring greens, but the result was still poisonous even with multiple changes of water.

Virginia-creeper (Parthenocissus quinquefolia) is a native plant that grows virtually everywhere. All parts of the plant are toxic to humans and other mammals. Ingestion causes intense mouth pain, nausea, diarrhea, vomiting, and abdominal pain. Swelling of the mouth and throat may cause swollen airways and asphyxiation.

Water-hemlock (Cicuta maculata), aka Spotted cowbane, is among the most toxic native plants in Virginia and has a toxicity rating of 6—and it’s one of the most gruesome poisons. It’s common near water, swamps, and wet seepage areas. All parts of the plant are highly toxic to humans, especially the roots. Symptoms include severe stomach pain, pupil dilation, nausea, vomiting, diarrhea, difficult breathing, violent convulsions, and swelling of the mouth. Grand Mal seizures can begin soon after ingestion and prove non-responsive to regular seizure medications. People can asphyxiate on their own vomit or shred their tongues with their teeth because they cannot open their jaws. Death typically follows within fifteen minutes to eight hours after ingestion.

Rhubarb has delicious stalks but poisonous leaves.

Other plants in my poison garden

  • Rhododendron — toxicity 6
  • Lily of the Valley — toxicity 6
  • Oleander — toxicity 6
  • Yew — toxicity 6
  • Daphne — toxicity 5
  • Mountain Laurel — toxicity 5
  • Rhubarb aka Pie plant — toxicity 4
  • Foxglove — toxicity 6

CAUTION! DANGER, DANGER, DANGER! Many of these plants are beautiful and/or sweet-smelling. Pay close attention when someone—especially a child—visits your poison garden.

Bottom line for writers: death is as close as your own backyard—or roadside—or pasture—or woods. . .