Dog's Mercury (Mercurialis perennis) - CAUTION: The fresh plant is poisonous and this poison is believed to be cumulative in its effects. Thorough drying or boiling seems to destroy its poisonous activity.

Fumitory (Fumaria officinalis) - CAUTION: Excessive dosages may cause diarrhea and stomachache.

Larch (Larix europaea) - CAUTION: Even small amounts of this herb can cause kidney damage internally as well as swelling and blisters externally.

Licorice (Glycyrrhiza glabra) - CAUTION: Do not use this herb if you have high blood pressure. Increased amounts of aldosterone in the body can cause a rise in blood pressure. In large quantities, Licorice can also deplete potassium levels in the body, which can be extremely dangerous. Those suffering from PMS might also want to avoid this herb, as it has the ability to cause water retention and bloating.

Lily of the Valley (Convallaria majalis) - CAUTION: Constituents of this herb called glycosides cause this herb to act like digitalis and can cause irregular heartbeat and upset stomach. Do not use without proper supervision.

Pansy (Viola tricolor) - CAUTION: Excessive dosages or prolonged, continual use can lead to skin problems.

Plum  (Prunus domestica) (Prunus americana) - CAUTION: Eaten in excessive quantities, fresh plums can cause cramping and diarrhea.

Pokeweed (Phytolacca americana) - CAUTION: Fresh or insufficiently cooked, this plant is poisonous, especially the root. The seeds inside the berries are also poisonous and especially hazardous to children.

Senna (Cassia marilandica) (Cassia acutifolia) - CAUTION: American senna is a very powerful laxative. It should be combined with herbs that ease griping or cramping as it can cause severe cramping.

Sorrel (Rumex acetosa) - CAUTION: Large amounts taken internally can irritate the kidneys and cause mild to severe poisoning.

Wahoo (Euonymus atropurpureus) - CAUTION: The leaves and fruit of this plant can cause symptoms of poisoning which range in severity from nausea to prostration.

*(Herbs in which Cautions exist.)