Contact Us Host an Event 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

Saturday - May 05, 2012

From: Liberty, TX
Region: Southwest
Topic: Poisonous Plants, Herbs/Forbs
Title: Is wild foxglove poisonous to dogs from Liberty TX
Answered by: Barbara Medford

QUESTION:

Is penstemon cobaea (wild foxglove)poisonous to pets, specifically dogs. I was thinking about adding this to my native Texan wild flower section of my backyard.

ANSWER:

If you look at our webpage on Penstemon cobaea (Wild foxglove), you will note this sentence under Condition Comments:

"Wild foxglove is not related to the true European foxglove."

So, we went looking for information on the European foxglove. Turns out it is from a different genus, Digitalis, not even related to the genus Penstemon, which is our "foxglove." Here is the information from that article on Digitalis purpurea

 Digitalis purpurea (Foxglove) These familiar biennial plants are members of the Snapdragon Family native to southern Europe and Asia, but highly prized in North American gardens for their tall spikes of beautiful, bell-like flowers, in pink, blue, or mauve, with dark spots inside the lip.  Foxgloves are the pharmaceutical source of the heart drug digitalis, which is poisonous in overdose. The plants are also helpful in preserving other species of cut flowers with which they may be arranged in a vase, or in stimulating the growth & endurance of garden root vegetables, especially potatoes, with which they may be planted. Poison is located in the sap, flowers, seeds, and leaves of Foxgloves, but the greatest concentration of the toxin occurs in the leaves, even dried ones.  Poison type: Digitoxin, a glycoside which stimulates the heart.  A carefully prescribed dose often has miraculous effects on people with heart conditions, but an overdoes may be fatal. Poisoning can occur accidentally from consumption of  the leaves or flowers by livestock, or children who are attracted by the showy flowers, or the nectar, both of which contain the glycoside poison. The sugar in the glycoside breaks down during digestion, releasing the active chemical.  Adults are occasionally poisoned by the misuse of herbal preparations- tea from dried Foxglove leaves is traditionally a diuretic- or by overdoses of prescribed digitalis.  Another possible cause of  is misidentification.  The leaves of Foxgloves are easily mistaken for those of Comfrey, which are traditionally brewed for tea; both share the same general form and a coasely hairy surface. Additional confusion occurs because, in its first year, Foxgloves produce only leaves, no flowers.  Foxglove leaves, however, have finely toothed edges, whereas Comfrey leaves are smooth.  Digitoxin is dangerous, so Foxgloves must be treated with caution.  Symptoms of poisoning are increased heart rate, leading to heart failure in the case of overdose. Other symptoms include stomach upset, mental confusion, and convulsions"

Now, let's look at the Penstemon genus, and see if it has any poisonous threats. From a previous Mr. Smarty Plants answer, here is a list of databases that would be useful in searching for poisonous plants. It is usually better to search on the scientific name, so we will look at these databases for Penstemon cobaea.

 

None of these showed any species of Penstemon as poisonous. But, you need to be really sure what you are buying-these common names can be tricky.

 

From the Image Gallery


Prairie penstemon
Penstemon cobaea

Prairie penstemon
Penstemon cobaea

Prairie penstemon
Penstemon cobaea

More Herbs/Forbs Questions

Short or mowable plant for walkway
June 03, 2008 - I'd like a short and/or mowable plant to use as a walkway in and around a vegetable garden in upstate NY. I was planning on clover, but I want to use a native plant if possible. The native clovers ...
view the full question and answer

Sunny and shady lawns from Austin
April 28, 2012 - My front yard has a large bed surrounded by a mix of St. Augustine and Bermuda grass. Last summers heat killed off about 90% of the St. Augustine, which we would like to replace anyway to conserve re...
view the full question and answer

Plants for a Austin thicket underlayer
July 25, 2014 - We live in Austin, west of 183. We are planning to put a thicket in our backyard, where there is no threat of deer. Anchoring the thicket are a clump of live oaks, a Texas persimmon, an Eve's Necklac...
view the full question and answer

Golden groundsel plants or seeds for Bulverde TX
October 02, 2011 - Where can I find golden groundsel, plants or seeds?
view the full question and answer

Deer resistant native plants for Eagle Scout project in Urbandale IA
April 27, 2013 - Mr. Smarty Plants, My son is planning his Eagle Scout Project doing some landscaping for the Iowa Primate Learning Sanctuary. The facility has asked him to use only plants native to Iowa. Can you su...
view the full question and answer

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