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
Not Yet Rated

Tuesday - May 01, 2012

From: West Lake Hills, TX
Region: Southwest
Topic: Invasive Plants, Non-Natives, Plant Identification, Problem Plants
Title: How Can I Tell an Invasive Thistle from a Native
Answered by: Mike Tomme


Mr Smarty Plants, I have some thistles coming up in my yard. I'd like to keep them if they are native, but not if they are invasive or non-native. How can I tell? My yard is a wild area in West Lake Hills, TX.


It would seem you have asked a simple question, but in reality you haven't. As you can see from this previous Mr. Smarty Plants answer, there are quite a few different plants that occur in central Texas that can be called some sort of thistle. As this answer makes clear, it can be difficult to tell the natives and non-natives apart and it requires a fair amount of research.

To help simplify mattes, I am going to assume that the thistles in your yard are the ones with the pink/lavender flowers that are blooming all around central Texas at this time of year. If you have the ones with yellow or white flowers, go back to that previous answer.

In her book Wildflowers of Texas, Geyata Ajilvsgi includes two thistles with pink/lavender flowers which I take to mean they are among the most common. They are:

Cirsium texanum (Texas thistle) - As you would guess from its name, this is a native thistle

Carduus nutans (nodding thistle) - This is a non-native. It is listed as an invasive plant by both Texasinvasives.org and the USDA. Another common name for it is musk thistle.

These are very similar in appearance. I sought help with identification methods from Minette Marr at the lady Bird Johnson Wildflower Center and she suggested a article published by the Oklahoma Cooperative Extension Service at Oklahoma State University entitled Thistles in Oklahoma and Their Identification.


From the Image Gallery

Texas thistle
Cirsium texanum

More Plant Identification Questions

Identification of Spaeralcea sp. Globe Mallow
March 31, 2008 - Let's do it again....my computer had some "issues" and I lost your answer.... I purchased a mallow from the WFC about two years ago...I was told at the time they had not yet identified the plant...
view the full question and answer

Identification of flower that looks like Callirhoe in NC
June 12, 2012 - Have a flower similar to callirhoe, but the blossum is fuchia, not purple and the foliage is light sage in color and fuzzy. It is very invasive. What is it? If you have an email address, I can send...
view the full question and answer

Texas wildflower guide with every flower listed
November 09, 2012 - Is there a Texas wildflower guide that contains every single flower that grows in the state? I have a few flowers on my land I haven't been able to identify because they aren't in the guide I have. ...
view the full question and answer

Identification of perennial with dark red/purple flowers
November 17, 2011 - Need to identify a lovely perennial here in Norfolk, Virginia. It reseeds itself, spreads, and lingers into the late fall. It has rather thick, dark green, alternate spatulate leaves at the base wit...
view the full question and answer

Plant identification
August 13, 2008 - Can you identify a shrub in my backyard? It has odd looking seed pods with three chambers and hard black seeds inside roughly 1/8" in diameter. The pods themselves are brown, hard shell, and hang d...
view the full question and answer

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


Wildflowers of Texas (2003) Ajilvsgi, Geyata.

Search More Titles in Bibliography

© 2016 Lady Bird Johnson Wildflower Center