En EspaŅol

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?


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
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
rate this answer
1 rating

Wednesday - June 26, 2013

From: Los Angeles, CA
Region: California
Topic: Poisonous Plants
Title: Major poisonous plants in California
Answered by: Nan Hampton


Hi! So I'm working on an art project that requires a comprehensive list of poisonous plants within California. I'm looking specifically however, for plants which are fatally poisonous (upon ingestion), and that are either native (preferably) or simply ubiquitous within California. I'm having a hard time finding such a list - if you could point me in the right direction, I'm willing to explore all venues. Thank you!


California Poison Control has a list of Toxic Plants with toxicity ratings in their Know Your Plants publication.  The ones designated as "4" are defined as Major with this explanation:

"Ingestion of these plants, especially in large amounts, is expected to cause serious effects to the heart, liver, kidneys or brain.   If ingested in any amount, call the poison center immediately."

Some of the plants on the list are native and some are not.  You can determine which are native and which are non-native introduced species by searching the USDA Plants Database using the scientific name.   Look for "Native Status" near the top left corner on each species' page.  It will indicate "N" native or "I" introduced.

You can determine more about the nature of the toxicity of the plant by checking (again, use the scientific name) on the following toxic plant databases.   Note that many of the toxic plant databases are geared towards livestock and not necessarily human concerns.

Poisonous Plants and Mushrooms of North Carolina

Plants Poisonous to Livestock and Other Animals–Cornell University

Poisonous Plants–Montana Plant Life

Canadian Poisonous Plants Information System

Pennsylvania's Poisonous Plants–University of Pennsylvania

Veterinary Medicine Library–University of Illinois at Urbana-Champaign

Livestock-poisoning Plants of California


More Poisonous Plants Questions

Removing Mountain Laurel Seed Pods from Austin
August 14, 2012 - Is it best to remove seed pods from Mt. Laurel or leave them on the tree?
view the full question and answer

Is Convolvulus equitans poisonous?
August 22, 2015 - Hello, Can you tell me if convolvulus equitans is poisonous? If so, can you tell me how poisonous and which parts are poisonous? I am considering putting this in my backyard but I have a dog and an...
view the full question and answer

Lantana poisonous to people, animals
May 07, 2008 - Mr. Smarty Plants, I read your response to the woman with the cow eating her plants over her neighbors fence. Just so you know- Lantana is poisionous. To humans and cattle. You recommended it as a...
view the full question and answer

Urushiol Oil Persistance?
September 09, 2015 - I'm trekking into poison ivy infested areas for work every other day. I make sure to wear long pants, long sleeves, boots, and long socks over my pants. I walk into my office to drop off supplies and...
view the full question and answer

Plants for farm animals from East Greenwich RI
May 03, 2014 - What type of perennial flowers and shrubs are safe to plant around farm animals (dogs, horses, chickens, turkeys) in New England climate?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center