Rent Shop Volunteer Join

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
Not Yet Rated

Wednesday - June 13, 2012

From: Devon, PA
Region: Mid-Atlantic
Topic: Poisonous Plants
Title: Is Asclepias incarnata poisonous to dogs?
Answered by: Anne Ruggles

QUESTION:

Is Asclepias incarnata safe in a farm/yard with plenty of dogs running around? What happens if a dog eats the leaves or seeds or pods? Is eating any of these fatal to dogs?

ANSWER:

Butterfly weed, milkweed, chigger-plant these are all common names for the plants of the genus Aesclepias which includes A. incarnata  which you ask about. In short, yes, the genus is poisonous. All parts of the plant are poisonous.

According to many sources including North Carolina State University, the University of Pennsylvania School of Veterinary Medicine, the ASPCA, and the Wildflower Center, all parts of the plant are poisonous in “large quantities.” It appears that livestock are most likely to ingest the plant.

Clinical signs of poisoning include profuse salivation, incoordination, and violent seizures. Early signs of poisoning are followed by bradycardia or tachycardia, arrhythmias, hypotension and hypothermia.  Death may occur from 1-3 days after ingestion.

However, the plants are premier food sources for butterflies, especially for Monarch butterflies. In the mid 1800s, naturalists observed that birds avoided eating butterflies whose larvae fed primarily on milkweed. It was later shown that the feeding larvae accumulated emetic cardiac glycosides that were retained and even concentrated in adult butterflies. Birds that ate the butterflies containing these glycosides vomited shortly after feeding and learned to avoid butterflies having the pattern typical of Monarch butterflies. Viceroy butterflies have evolved the ability to mimic the monarch’s appearance thus avoiding predation by birds who mistake the mimic for the distasteful monarch. 

 

From the Image Gallery


Swamp milkweed
Asclepias incarnata

More Poisonous Plants Questions

Are Viguiera dentate leaves toxic to dogs?
November 26, 2014 - Many dogs on the Turkey Creek Nature Trail in Emma Long Metropolitan Park love to snack on the leaves of the Viguiera Dentata plants. The leaves SEEM to be harmless. I am writing to request informat...
view the full question and answer

Non-toxic Groundcover for North-Central Texas
April 07, 2011 - I need a creeping ground cover for shade that is non-toxic to dogs. I had planned on Swedish ivy until I read it was toxic. Is Asian jasmine toxic? Or, do you have any suggestions?
view the full question and answer

Toxicity of seeds of Texas Mountain Laurel for dog
April 07, 2007 - I have a Tx Mountain Laurel that is in 1 end of a dog pen. I just heard the seeds are poisonous. Is this true & should we pull the seeds off so the dog can't reach them to eat? Thanks for your assist...
view the full question and answer

Is Fern-like Plant with White Flower Poison Hemlock?
May 06, 2014 - I have a fern-like plant which produces white flowers that uncurl from the stem as the plant starts to grow. Is this poison hemlock?
view the full question and answer

Evergreen hedge non-toxic for horses and goats in Muskogee, OK
March 31, 2009 - I live in northeastern Oklahoma. I am trying to find an evergreen hedge, 6-8 ft in height, 4-6 ft spread that is not harmful to horses or goats. Everything that I have found is for Zone 8 or 9.
view the full question and answer

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