**I am not an expert so please before you use any herb/plant do your own research.
Arnica; poisonous in large amounts which can cause serve gastroenteritis, fever, nausea, dizziness, abnormal pulse rate, diarrhea, skin reactions, and internal bleeding of the digestive tract.
Azalea; poisonous and causes nausea, vomiting, depression, difficulties breathing, coma, and it is rarely lethal.
Balm of Gilead; can cause skin irritation, serve stomach upset, and pregnant/breastfeeding woman should avoid.
Belladonna; very deadly poisonous causes blurred vision, staggering, loss of balance, dry mouth and throat, headache, rash, constipation, confusion, hallucination, and convulsions. Careful when handling because it can be adsorbed through skin.
Bleeding Heart; may be poisonous in large amounts which cause convulsion and other nervous symptoms.
Blue Flag; nausea, vomiting, irritation of the mouth, throat, digestive tract, skin, headaches, watery eyes.
Bryony; all parts of are poisonous and can cause death, lethal if consumed.
Buttercup; irritant juices may severely damage the digestive system.
Calamus; toxic in large dosages and causes hallucinations, nausea, and vomiting.
Calabar Bean; extremely toxic which can cause excessive sweating and saliva, reduced pupil size, nausea, vomiting, diarrhea, irregular heartbeat, blood pressure changes, confusion, seizures, coma, muscle weakness, paralysis, serve breathing problems, and death.
Camphor; serve allergic reaction which include rashes, hives, itching, difficulties breathing, tightness in chest, swelling of the mouth, eyes, face, lips, or tongue.
Castor Oil Plant; poisonous and causes burning sensation in mouth and throat, abdominal pain, bloody diarrhea. In the next several days dehydration, drop in blood pressure, and decrease in urine. Unless treated death can be within 3-5 days.
Celandine; nausea, dizziness, fatigue, fever, and liver damage.
Christmas Rose; causes burning of the mouth, eyes, throat, oral ulceration, gastroenteritis, and vomiting blood.
Cowbane; poisonous and can attack the central nervous system which can induce seizures.
Daffodil; can cause nausea, diarrhea, vomiting, and can be but usually not fatal.
Daphne; poisonous, causes burns to the mouth and the digestive tract then followed by a coma. Can be fatal.
Dog’s Mercury; poisoning will appear in the next few hours which includes vomiting, pain, gastric and kidney inflammation, sometimes inflammation of the jaw and cheeks, and drowsiness.
Elderberry; poisonous and causes nausea and digestive upset.
Elephant Ear; all parts are poisonous and causes irritation of the mouth and tongue, can be fatal.
Ergot; can be fatal and can also cause nausea, vomiting, muscle pain or weakness, numbness, itching, vision problems, convulsion, confusion, spams, and unconsciousness.
Gelsemium; extremely poisonous even in small amounts very toxic and can cause headaches, vision problems, difficulties swallowing, dizziness, muscle problems, seizures, breathing problems, and slowing of the heart.
Golden Chain; serve poisoning which causes excitement, staggering, convulsions, and coma. This can be lethal.
Foxglove; large amounts can cause irregular heartbeat, digest upset, mental confusion, and can be fatal.
Hellebore; likely unsafe if ingested or applied to skin which can cause irritation of the mouth and throat lining and also slow down the heartbeat. Large dosages cause vomiting, diarrhea, difficulties swallowing, nerve problems, blindness, convulsions, paralysis, difficulties breathing and death.
Hemlock; stomach pains, vomiting, and progressive paralysis of the central nervous system.
Henbane; cause dilated pupils, hallucinations, increased heart rate, convulsions, vomiting, hypertension, and ataxia.
Holly; berries can be deadly and the leaves can cause nausea, diarrhea, vomiting, stomach and intestinal problems.
Honeysuckle; can cause allergic reactions which include rashes.
Horse balm; gastrointestinal irritation, nausea, dizziness, and painful urination.
Hyacinth; nausea, vomiting, diarrhea, and can be fatal.
Ilex; serve allergic reactions which include rash, hives, itching, difficulties breathing, redness, burning, swelling of the mouth, eyes, face, lips, or tongue.
Iris; serve digest upset.
Ivy; poisonous, causes stomach pains, labored breathing, and possible coma.
Jewelweed; dangerous when consumed in large amounts.
Jerusalem Cherry; nausea and vomiting and occasionally fatal especially to children
Jimsonweed; do not inhale or consume, can cause many toxic effects like dry mouth, extreme thirst, vision problem, nausea, vomiting, constipation, fast heart rate, hallucinations, high temperatures, seizures, confusion, loss of conciseness, breathing problems, and death.
Laburnum; intense sleepiness, vomiting, excitement, staggering, convulsive movements, frothing at the mouth, unequally dilated pupils, coma and death.
Larkspur; digestive upset, nervous excitement, depression, and can be fatal.
Laurel; poisoning produces anorexia, profuse salivation, depression, uncoordination, vomiting, watering of the eyes, difficulties breathing, weakness, cardiac distress, convulsion, coma, and eventually death.
Lily of the Valley; irregular heartbeat and pulse accompanied by digest upset and mental confusion.
Lobelia; potentially toxic which can cause vomiting, it also can interfere with medication.
Jack-In-The-Pulpit; produces allergic reactions and causes skin, mouth, throat irritation, swelling, burning, difficulties breathing, and stomach upset.
Kava Kava; can cause liver problems, nausea, rapid heartbeat, vomiting, drowsiness, numbness around mouth, hallucinations, kidney effects, shortness of breath, and disorientation.
Mandrake; poisonous which can cause blurred vision, dryness of the mouth, difficulties urinating, headaches, vomiting, rapid heart rate, and hallucinations.
Mayapple; diarrhea and serve digestive upset.
Mistletoe; poisonous and causes gastrointestinal discomfort, diarrhea, weak/slow pulse, seizures, and it is rarely lethal to humans.
Morning Glory; toxic and causes diarrhea, gastrointestinal upset, disorientation, ataxia, anorexia, and hallucinations.
Mugwort; use in a well ventilated area and with the right dosage, too much can be lethal.
Nightshade; fatal and intense digestive disturbance and nervous symptoms.
Oak; poisonous in large amounts and gradually affects the kidneys.
Oleander; extremely poisonous can cause heart effects, serve digest upset and even death.
Pennyroyal; can cause serve liver and kidney damage and also stomach pain, nausea, vomiting, burning of the throat, fever, confusion, restlessness, dizziness, high blood pressure, abortions, and brain damage.
Periwinkle; contains poisonous chemicals and should no be ingested can cause nausea, vomiting, hearing loss, hair loss, dizziness, bleeding, nerve problems, seizures, liver damage, low blood sugar, and even death.
Pleurisy Root; can cause serve heart problems, nausea, vomiting, and skin rashes.
Poinsettia; skin rashes, serve eye irritation, and irritation or burns to the mouth, throat, stomach, and intestinal lining.
Pokeweed; all parts are poisonous and when handling use gloves because some chemicals can pass through skin and affect the blood and it also causes nausea, vomiting, cramping, stomach pain, diarrhea, low blood pressure, difficulty controlling urine, and thirst.
Rhubarb; fatal and large amounts can cause convulsions, coma, and a rapid death.
Snakeroot; can be fatal, cause nausea and vomiting.
Spurge; unsafe and has chemicals that cause cancer, other effects include nausea, diarrhea, vomiting, burning of the mouth, dilated pupils, dizziness, painful bowel movements, near unconsciousness, irregular heartbeat, rashes, reddening, itching, burning, and blisters.
St John’s Wort; can be poisonous and cause fatigue, dizziness, confusion, and dry mouth.
Skullcap; pregnant women should not use it can cause a miscarriage
Thorn Apple; abnormal thirst, distorted sight, delirium, incoherence and can be fatal.
Uva Ursi; can cause skin discoloration, headaches, tinnitus, dizziness, muscle twitching, tremors, convulsion, seizures, nausea, vomiting, irritation to the skin and eyes.
Wahoo; poisonous and potentially deadly, symptoms include serve upset stomach, bloody diarrhea, fever, shortness of breath, unconsciousness, spams and coma.
Wisteria; mild to serve digestive upset, many children have been poisoned by this plant.
Wolfsbane; also know as Aconite, disables nerves, lowers blood pressure, and can stop the heart. Avoid skin contact.
Wormwood; can cause diarrhea, vomiting, nausea, insomnia, restlessness, vertigo, and seizures.
Yellow Jasmine; poisonous and cause nausea and vomiting.
Yew; fatal, death is usually sudden without any warning symptoms.