What's the Story, Morning Glory?

Morning glories are poisonous beauties. Know your plants to keep your household safe.
By: Maureen Gilmer

Morning Glory

©National Gardening Association

National Gardening Association

One afternoon I ripped out a thicket of morning glory vines that left my skin sticky with sap from the cuttings. I felt odd that evening, then woke up the next morning with a blinding migraine headache.

It was preceded with a visual aura of visual patterns akin to psychedelic hallucinations. That was followed by lower-level migraine for days and persistent dizziness that lasted a week. I know now it was all caused by morning glory poisoning. Why? Because my work partner woke up sick with the same symptoms. It was no coincidence.

Buried in the academic texts of medical botany there are references to morning glory, Ipomaea violacea. This native of Mexico is an incredibly beautiful perennial vine grown as an old-fashioned annual garden flower further north. Being frost-tender, plants usually die with the first cold snap of fall.

The plant known by the Aztecs as "ololiuqui" (that which makes one dizzy) was used in divination rituals. The shaman would consume it, then fall into delirium in which he could hear messages from the gods. Morning glory is still used in this way in remote parts of Mexico.

So what's in morning glory that's so painfully psychoactive and potentially toxic? My books revealed the same alkaloids shared by ergot, a fungus of rye that produces profound vascular spasms and hallucinations if consumed.

In Europe it would be responsible for the devastating disease, St. Anthony's fire. In fact, morning glory contains d-lysergic acid amid in its seed. This chemical presence in morning glory is potentially lethal, and from personal experience I can attest to its long, painful hangover.

Transdermal patches are now widely used for administering nicotine and birth-control medications. This illustrates the porosity of human skin. Plants such as nightshades that contain potent chemicals can result in transdermal poisoning if handled in quantity. This penetration factor skyrockets when you're sweating and your skin pores are wide open.


Angel's trumpet, a South American shrub of the nightshade family, contains potent chemicals in its leaves and flowers. (SHNS photo by Maureen Gilmer / Do It Yourself)

Angel's trumpet, a South American shrub of the nightshade family, contains potent chemicals in its leaves and flowers. (SHNS photo by Maureen Gilmer / Do It Yourself)

Mexican immigrant gardeners in Los Angeles are reluctant to handle angels trumpets, which are species of genus Brugmansia. These spectacular ornamental nightshades contain serious chemical constituents such as atropine. The Aztecs handed down their knowledge of transdermal poisoning, and to this day Mexicans are particularly cautious if they have open cuts, blisters and wounds on their hands.

As a lifelong garden authority I'm embarrassed that morning glory caught me off guard. I should have worn rubber gloves and long sleeves to keep all plant juices from skin contact. But, frankly, I'd never worked on such a huge morning glory, so there was never enough sap to cause a problem before.


With its bright red flowers, crown of thorns is a Euphorbia that contains toxic white sap. (SHNS photo by Maureen Gilmer / Do It Yourself)

With its bright red flowers, crown of thorns is a Euphorbia that contains toxic white sap. (SHNS photo by Maureen Gilmer / Do It Yourself)

It's important to know the major offenders so you're not caught barehanded. Common foxglove contains digitalis, a powerful cardiac stimulant can cause serious poisoning. The sap of the entire family of euphorbias, including poinsettia, is also toxic, often causing surface blistering of the skin. Beware of Euphorbia truncata, popularly known as firesticks, which bleed profusely, potentially entering the bloodstream through the skin. Monkshood and castor bean also should be handled with care.

It is always best to consider all plants poisonous unless you know otherwise. Poisoning through the skin is not likely unless you are handling a lot of plant material, particularly in the heat. But this can often be the case if you're clearing ground, weeding and rehabilitating an overgrown homesite in the summer.

If you must grub out some of these bad boys, be sure to wear protection. Pets and kids are also vulnerable to when rolling around in the bushes. Know your plants to keep your household safe.

I have not removed my Ipomaea violacea because they are such exquisitely beautiful plants. But rest assured I now afford them a great deal of respect after learning the hard way that morning glories can indeed become a real nightmare.

Here are the poisonous plants of the gardens:

  • Acontium spp: Monkshood
  • Atropa belladonna: Deadly Nightshade
  • Brugmansia spp: Angel's Trumpet
  • Conium maculatum: Poison Hemlock
  • Datura spp: Devil's Weed
  • Digitalis purpurea: Foxglove
  • Euphorbia spp: Spurge
  • Gelsemium sempervirens: Carolina Jessamine
  • Helleborus foetidus: Christmas Rose
  • Hyocyamus niger: Black Henbane
  • Ipomaea violacea: Morning Glory
  • Nerium oleander: Oleander
  • Ricinis communis: Castor Bean

(Maureen Gilmer is a horticulturist and host of Weekend Gardening on DIY-Do It Yourself Network. E-mail her at mo@moplants.com. For more information, visit : www.moplants.com or www.DIYNetwork.com. Distributed by Scripps Howard News Service.)

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