Host an Event Volunteer Join Tickets

Support the plant database you love!

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

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

QUESTION:

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.

ANSWER:

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

Identity of plant called 'Bell-flowered Yucca' associated with Lynn Lowrey
January 20, 2011 - Please help identify a plant, the seeds of which are labeled "Bell Flowered Yucca" and " H. lowyrii" (or, presumably, some variant of Lynn Lowrey's name). I believe that this seed was collected ...
view the full question and answer

Possible cinnamon-scented plants in Mississippi delta
July 11, 2005 - I used to live in Mississippi and now live in Illinois. I am trying to find what plant or tree has a strong cinnamon-like scent that fills the air. I noticed this scent driving through the delta in Mi...
view the full question and answer

Plant Identification
April 01, 2009 - I have small shiny red berries growing on a tropical appearing shrub with green and marled yellow leaves. The leaves have widely serrated edges. The berries have a large seed inside and very little fl...
view the full question and answer

Plant identification
June 12, 2014 - We live in Magnolia TX and have a shrub we can't identify. It's evergreen and has waxy leaves with a serrated edge that are about an inch in length. They have pink flowers and they grow to ab...
view the full question and answer

Flower with spike of yellow flowers with hairy purple filaments
July 03, 2012 - Fuzzy purple stamens! I can't find this plant identified anywhere. Blooms abt 1" or a little more across. 5 yellow petals, 5 sepals, & 5 stamens with yellow anthers, & the filaments are covered wi...
view the full question and answer

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

Bibliography

Wildflowers of Texas (2003) Ajilvsgi, Geyata.

Search More Titles in Bibliography