Saturday, June 1, 2013

Ricin And Other Poisons Found In Our Plants.

Very cool, but deadly, Ricinus flower
head  ©2013 BDG

Ricinus or Castor Oil Plant is considered one of the most poisonous plants in the world, and it is the source of the poison Ricin that has been in the news recently.  I made this connection recently while listening to a program on NPR talking about the deadly nature of the toxin and realized that I have had this ornamental annual in my garden before.   I knew this plant was poisonous, as are many common plants in my and almost everyone's garden, but I had no idea that it was 'that' plant.

Both Castor Oil and Ricin are derived from the seed of the plant.  The oil is not toxic and has medicinal and industrial uses, while Ricin is a deadly poison.  All parts of the plant are poisonous, to a lesser degree, but the seeds are the most poisonous with a few capable of killing animals and children.  An article by Cornell University on Ricinus provides a comprehensive summary.

A trio of poisonous plants in my garden: Yew,
Rhododendron and Azalea.  ©2013 BDG

This led me to take a look at poisonous plants in general.  Most everyone in New England has a plant considered toxic in their garden, however, poisoning or death from plants is not a regular occurrence.  Here is a list of common garden plants that may be poisonous, as well as the ASPCA Poisonous Plant List.

Wisteria, Rhododendrons, Azaleas, Laurel, Yew, Hydrangea, Daphne are some common woody plants that have poisonous parts.  While most would require significant ingestion for serious consequences, it is good to know that some very common plants can be dangerous for animals and young children.  Daffodils, Delphinium, Monkshood, Lily of the Valley, Iris, Foxglove, Bleeding Heart, Mums, English Ivy and Euphorbia are some common perennials with parts that are toxic to animals and people.

Hydrangea flowers can be toxic, but at size
of a small soccer ball I am not sure how
to eat this.  ©2013 BDG

With animals that love to dig and chew, it is recommended that you not keep these plants in areas where they have regular access.  For children, it is the decorative parts that are most often a concern.  You may remember Yew plants when we were kids that had those irresistible berries that were ammunition in battle.  The berries are quite poisonous.  Yews happen to be dioecious plants(either male or female plants) and most plants in the trade nowadays are male that don't bear the berries.

Daffodil bulbs are poisonous which is why Squirrels and other furry varmints don't dig them up.  The critters know this and planting Daffodils around other sensitive bulbs can minimize damage.  Foxglove (Digitalis) is used as a common heart medicine, but can be dangerous if ingested.  I didn't realize that Hydrangea flowers can be toxic, so definitely not a flower I will be adding to the top of my salad.

The roots of bleeding hearts are toxic.  ©2013 BDG

We have lived with many of these plants in our gardens for years and we, our children and our pets have survived, but it is always good to know a little more about potential dangers around us.  It is not necessary to go out and dig up every potentially dangerous plant, as many of these plants may only cause stomach upset or diarrhea with minimal consumption.  However, with all of the introductions of exotic annual plants from sub-tropical and tropical parts of the world, it might be good to be cautious placing them in containers that are easily accessible to our young children and animals.

As cool as the Ricinus plant is with its foliage and flower, I don't think I will bring it into my garden while I have two curious little Beagles and a teenage son.


  1. I didn't realize that hydrangea's are poisonous! I agree with you; while many of our common and favorite flowering plants are poisonous, it is reasonable to draw the line somewhere. Thanks for the informative post!

  2. It's interesting to think about how many poisonous plants are also sources of beneficial medicines (digitalis being one example). I owe my life to chemotherapy with the drug Taxol, which is made from yew. -Jean

    1. I did not know that Taxol is a derivative of Yew, but the name makes the obvious connection. Do you have a special Taxus specimen in one of your gardens, there are so many interesting cultivars?

  3. I once pulled up all my monkshood because I was worried my kids/dogs would munch it. Have you read Amy Stewart's book Wicked Plants? It's pretty eye opening how deadly some of our favorite plants can be. Great post!

    1. I have not read the book, I will take a look. Funny, because I though it might make an interesting book when you add in the historical context.

  4. Knowledge is power. There are lots of small children roaming our neighborhood. So even though I would like to plant some holly for a privacy hedge, and even though holly berries are probably only mildly poisonous (according to most sources I can find online), I'm going to err on the side of caution and not plant any near the property perimeter.

    Especially in our society where many people have very little knowledge of or respect for plants, I think it's even more risky to put poisonous plants in a garden. In older times, knowledge of which plants were safe and which were dangerous was probably more widespread. But much of that knowledge has fallen by the wayside these days, at least among the general populace.