Host an Event Volunteer Join Tickets

Support the plant database you love!

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
13 ratings

Thursday - December 01, 2011

From: Knoxville, TN
Region: Southeast
Topic: Poisonous Plants
Title: North American Plants with Poisonous Thorns
Answered by: Becky Ruppel

QUESTION:

Are there any plants in North America that possess poisonous thorns?

ANSWER:

In North America there are few plants that have poisonous thorns.  The members of the Solanum (nightshade) genus have thorns and are reported to cause injuries that are slow to heal due to poisonous thorns.  Many members of the nightshade family (Solanaceae) have many poisonous parts (i.e. leaves, stems, fruit, roots, seeds) that cause severe irritation to mammals.  The members of this family are widely distributed across North America. 

Another group of plants that have poisonous “thorns” is Stinging Nettles.  They have tiny hairs on the underside of their leaves that ‘sting’ and cause skin irritation and a burning sensation if they are brushed against. 

Finally, most plants that have thorns can cause mechanical injury, and some injuries result in pieces of the thorn breaking off in the skin.  It would seem as if these plants had poison, but in fact, the swelling and redness around a wound is caused by a foreign object logged in the skin. 

Considering plants outside of North America there are several plants from Africa that have poisonous thorns such as Gymnosporia buxifolia or Dichrostachys spp

I acquired my information about thorny plants from the Botanical Dermatology Database.  There is lots of information there if you would like to read further about the affects of plants with thorns. 

 

More Poisonous Plants Questions

Precautions to take with Jack-in-the-Pulpit, Arisaema triphyllum
September 13, 2009 - Are there precautions to take, such as wearing gloves while separating the seeds from the Jack In The Pulpit berries. The photos I have seen have gloved hands. I've read that the plant is toxic if in...
view the full question and answer

Is Artemesia ludoviciana allelopathic?
February 20, 2009 - I recently read that Artemisia ludoviciana is allelopathic to some other plants. I planted some last fall between a rusty blackhaw viburnum and a Mexican buckeye. Do you know whether it is phytotoxi...
view the full question and answer

Remedy for sore finger scratched by an Agave plant
October 18, 2013 - I scratched my ring finger on a Agave plant this afternoon. It did bring blood to the surface and i washed it off. Where the scratch is, is very tender and it is swollen and tingles. Any suggestions f...
view the full question and answer

Non-Toxic Flowering Vine for Sunny Trellis in California
March 12, 2015 - I am looking for a flowering trellis plant that is non-toxic to my dog, will grow in the California area that I live in, and will be in full sun.
view the full question and answer

How to Remove Pokeweed in Greenburg, Pennsylvania
September 10, 2010 - Last year I purchased a home with 3 acres of land and it is infested with pokeweeds,Phytolacca americana! I have small children and know this is a poisonous plant. Could you please tell me a way to ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.