Four o’clock is the most common name for the genus of flowering plants called Mirabilis. Species from this group of plants are native to South and Central America as well as Southwestern United states. The most common species of four o’clock is Mirabilis jalapa. It was originally cultivated in the Andes where it was used for medicinal purposes, primarily as a purgative but the plant is also rumored to have some antiviral properties. M. jalapa is grown as a garden plant in many parts of the United States. In warm climates, it is a hardy perennial; even in moderately cold climates it will grow back from large tuberous underground roots.

The plant grows to be about 35 inches (90 cm tall) with funnel-shaped flowers of multiple colors. Different colored flowers may be seen growing on the same plant, and flowers may even have sections with contrasting pigment. Colorado four o’clock, Mirabilis multiflora, is native to southwestern United States where it grows as a wild flower. Like M. jalapa, M. multiflora was supposed to have medical properties and some Indian tribes consumed the powdered roots as an appetite suppressant.

One species of four o’clock, Mirabilis expansa, is grown as  a food crop in some Andes cultures, however most four o’clock species found in the United States contain alkaloids which can be moderately toxic in large doses. The alkaloid trigonelline, found primarily in the roots and seeds, causes irritation to the skin and to the digestive tract if eaten. Since dogs rarely eat roots, chewing and swallowing the seeds are the primary concern, but symptoms of gastrointestinal upset are typically mild and pass on their own. Crushed seeds or roots can also cause skin irritation upon contact.

Four o’clock is a garden flower that also grows wild in some parts of southwestern United States. Alkaloids in the roots and seeds can be moderately toxic for dogs. Most symptoms are limited to vomiting and diarrhea as well as topical skin irritation.

These are the symptoms you will see with four o’clock poisoning.

There are many different types of four o’clock species. These are some of the most well-known.

Mirabilis jalapa (Four O’Clock, Marvel of Peru, Clavillia, Beauty of the Night) – grown commonly as a garden flower. The seeds and roots are considered toxic.

Mirabilis multiflora (Colorado Four O’Clock) – native to southwestern Unites States, from Colorado west to southern California. The seeds and roots are considered toxic.

Mirabilis expansa (Muaka, Chago) – hardy plant that grows at high altitudes in the Andes. The large root and shoots are edible. M. expansa was an Incan food crop and is still grown in some South American Countries.

Four o’clock poisoning will be diagnosed based on a history of ingestion or topical contact as well as symptoms. If your dog consumes a non-food plant from your garden, it’s a good idea to call your veterinarian for advice. If symptoms are severe, or you think the plant may be highly toxic, contact a poison helpline. Have a sample of the plant ready to describe. The agent will also need to know your dog’s size and weight and how much you think was ingested. Gastrointestinal symptoms from four o’clock ingestion typically pass by themselves and most veterinarians won’t suggest an office visit, unless your dog is very small or you think a very large number of seeds have been consumed. If symptoms don’t clear up in a day or two, you should have your dog evaluated.

If you think your dog has eaten four o’clock seeds or roots, you should remove any partially chewed material from his mouth. Gently clean the muzzle or any other area of topical exposure. Give your dog water or milk to reduce the concentration of toxins in the stomach. Don’t induce vomiting unless recommended by a veterinarian. Most cases of four o’clock poisoning won’t require further treatment.

If your dog ingested a large number of four o’clock seeds, the veterinarian may need to induce vomiting. Activated charcoal may be given to limit absorption in the gastrointestinal tract. Cathartic medication can help move toxins through the system faster.

If symptoms are very severe, the veterinarian may give antiemetic medication to stop vomiting. Additional fluids may be necessary to prevent dehydration. Topical creams or ointment may be prescribed for skin irritation.

Most dogs will make a full recovery after four o’clock ingestion. Symptoms typically pass on their own and even severe cases can be adequately treated by a veterinarian. Four o’clock plants should be handled with caution around dogs, especially those that like to chew on nuts or seeds. These aren’t the worst plants to have in your garden, but they could be problematic if your dog is eating them regularly. Make sure your dog has a healthy diet with plenty of roughage. Plant dog-safe grasses around your house and encourage your dog to chew on these rather than garden flowers.