En Español

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

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
1 rating

Friday - June 15, 2012

From: King, NC
Region: Southeast
Topic: General Botany, Poisonous Plants
Title: What is white sticky substance in the Mandevilla vine?
Answered by: Nan Hampton


When I was watering my Mandevilla one of the vines broke and there was a white, sticky substance that came out of the vine. I was just curious as to what that is.


The white sticky substance is the sap of the Mandevilla.   Mandevilla species, native to South America, are members of the Family Apocynaceae.  The majority of the members of the family have this thick milky sap sometimes called latex.  Mandevilla spp. are not known to be poisonous but are related to species that are according to the Poisonous Plants of North Carolina database.   The Tortoise Table says that the sap of Mandevilla causes skin irritation in some people and, thus, should be avoided.   This website also suggests that since another member of the family, Oleander (Nerium oleander), is extremely toxic, it would be better to err on the side of caution and not feed the plant to your tortoise (if you have one) or eat it yourself!


More General Botany Questions

Native North American bulbs
August 19, 2011 - I saw your list of 4 lilies native to the Northeastern United States, which was very helpful. What other bulbs are native to North America? Although I garden in Connecticut, I am interested in learn...
view the full question and answer

Grafting stone fruit
April 02, 2009 - Do you know of anyone grafting the new low chill stone fruit trees to the Mexican plum to minimize cotton rot? Or would it even work?
view the full question and answer

Liquid glucose as substitute for sunlight from New York City
December 16, 2012 - I am curious to find out whether liquid glucose can be poured as water for mung bean plants as substitute for no sunlight. Is the possible? Will a specific amount of glucose need to be used? Can liqui...
view the full question and answer

Propagating a white cultivar of Texas Mountain Laurel (Sophora secundiflora
September 09, 2016 - I am trying to propagate a white cultivar of the Texas Mountain Laurel. I plan to use bee sticks and pollinate the plant. Are the plants self fruiting or do I need to find another white mountain laure...
view the full question and answer

How is native range changed in the scientific record?
March 28, 2011 - I am accessioning Pachysandra procumbens for the Baker Arboretum. These plants were made from cuttings of a native stand here in Warren County (Western KY). How does the record get amended to...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2016 Lady Bird Johnson Wildflower Center