dumb cane.

Name: Dumb Cane or Dieffenbachia
"This plant that we have in our homes and
offices is extremely dangerous! This plant is
common in Rwanda. It is a deadly poison,
most specially for the children. It can kill a
kid in less than a minute and an adult in 15
minutes. It should be uprooted from
gardens and taken out of offices. If
touched, one should never touch his/her
eyes; it can cause partial or permanent
blindness."

The plant depicted in the photograph is in fact a dieffenbachia, a species commonly used as a potted house plant because of its attractive appearance and its suitability for indoor, low light intensity growing environments. Dieffenbachia is indeed poisonous to humans and animals if parts of the plant are ingested. Dieffenbachia is also known as "Dumb Cane" because of the toxic effect it can have on the mouth and tongue if chewed.

However, this warning quite significantly exaggerates the risk of death associated with dieffenbachia poisoning. The results of dieffenbachia poisoning are normally not life threatening and victims usually make a full recovery. Given that eating the plant may potentially cause swelling severe enough to block the victim's airways, death is a possible result. However, research indicates that actual fatalities in humans are extremely rare. Certainly, there are no credible medical reports that back up the suggestion in the warning message that death is a common and very rapid result of dieffenbachia poisoning. An article discussing caladium, dieffenbachia, and philodendron plant poisoning published on the Emedicine website notes:

Patients with history of oral exposure (chewing and/or swallowing) have been reported to have severe swelling, drooling, dysphagia, and respiratory compromise, but this is not common. In a large retrospective study of 188 patients with plant oxalate exposure, all cases were determined to be minor and all resolved with minor or no treatment. Patients can also experience dermal and ocular exposure, resulting in contact dermatitis or keratoconjunctivitis. Symptoms that result from these routes of exposure also appear to resolve with supportive care. The serious complication of aortoesophageal fistula following ingestion of a dieffenbachia leaf in a girl aged 12.5 years has been described in a single 2005 case report. The girl recovered following surgical intervention.

And, the claim that rubbing your eyes after touching the plant can cause permanent blindness also seems to be an exaggeration. The Emedicine article notes that "Ocular exposure may result in eye pain, redness, and lid swelling", but makes no mention of permanent blindness. Other medical articles describe dieffenbachia induced corneal injury but again make no mention of permanent blindness.

While the warning message is overblown and inaccurate, it should be stressed that ingesting dieffenbachia can certainly cause a number of distressing and painful symptoms. Information about dieffenbachia poisoning published on the Medline Plus website records the following poisoning symptoms:

• Burning in mouth or throat
• Damage to cornea of the eye
• Diarrhea
• Eye pain
• Hoarse voice
• Nausea or vomiting
• Swelling in mouth or tongue

It should also be noted that dieffenbachia related poisoning among household pets does regularly occur and in some cases has resulted in the death of the animal.

Given that it is actually quite important that householders are aware that their dieffenbachia plants are potentially poisonous, especially if they are parents or guardians of younger children or have pets, the email does have some merit as a warning. Unfortunately, the email significantly erodes its potential usefulness as a cautionary tale by so blatantly misrepresenting the potential danger of the plant. Another quite serious flaw in the warning message is that it does not actually include the name of the plant under discussion. Some versions do not even include the image of the plant - which incidentally was apparently "borrowed" from the Lahore Nursery website for use in the message - thus rendering the warning virtually useless.