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
Not Yet Rated

Tuesday - September 02, 2008

From: San Antonio, TX
Region: Southwest
Topic: Poisonous Plants
Title: Curing plant rash
Answered by: Joe Marcus


I went walking in the woods a few weeks ago, and my leg swiped some kind of cactus or something. It scratched me up and I had to remove little white spines with tweezers. I developed an intensely itchy rash that three weeks later is just as bad as when it first happened. It is not poison ivy or anything.. I have no idea what it is and it is not getting any better. I tried using Tea Tree oil and Shea oil.. it helps a little but has not cured the problem. I don't want to take any pharmaceutical drugs. Do you know how I can resolve this naturally?


We don't think we can answer your question since giving medical advice is not really in our province, but it seems that after three weeks you might want to consult with a medical doctor.  However, we may be able to help you identify the cause.  If the offending plant was a cactus, it was likely Cylindropuntia leptocaulis (Christmas cactus), also known as Pencil cactus or Tasajillo.  Other possible offenders include Urtica chamaedryoides (heartleaf nettle), Cnidoscolus texanus (Texas bullnettle), and Tragia spp, (Noseburn). A less likely candidate (because it's not native to that area but occurs not too far away) is Cevallia sinuata (stinging serpent),  Finally, any number of insects with stining hairs, including saddleback caterpillars and stinging asps may have assaulted you.


From the Image Gallery

Texas bullnettle
Cnidoscolus texanus

Branched noseburn
Tragia ramosa

Stinging serpent
Cevallia sinuata

Cylindropuntia leptocaulis

Betonyleaf noseburn
Tragia betonicifolia

More Poisonous Plants Questions

Are seeds of Tecoma stans (yellow bells) toxic to birds
June 22, 2008 - We have several Tacoma Stans in our yard and several pets (dogs & a Cockatoo). My Too is very interested in the beans of this plant. Are the beans poisonous to birds? Dogs?
view the full question and answer

Plant identification for shrub in Florida
September 03, 2011 - On our street we have ornamental shrub planted in the median that has small waxy green leaves, produces small fragrant white flowers, and red berries with white pulp and small seeds on the inside. Th...
view the full question and answer

Root cuttings for non-native, poisonous oleander from Mobile AL
December 16, 2010 - I need help with best method to root cuttings from my oleander tree. Please advise best method. Thanks
view the full question and answer

Are Eve's Necklace seeds poisonous to dogs from Plano TX
May 09, 2013 - Are the seed pods on eve's necklace poisionous to dogs?
view the full question and answer

Information about Rosa acicularis
March 07, 2008 - Hi: At your site under "Benefit" it is mentioned that the seeds, leaves bark and twigs of Rosa acicularis Lindl. can be fatally poisonous to humans and animals. None of my past or present studies h...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
© 2015 Lady Bird Johnson Wildflower Center