Native Plants

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

Monday - July 21, 2014

From: Austin, TX
Region: Southwest
Topic: Invasive Plants, Problem Plants, Trees
Title: Fast-spreading desert-type tree with thorns in yard
Answered by: Nan Hampton

QUESTION:

There is a fast spreading tree in my backyard - many multiple almost symmetric flat green oval leaves on either side of the stem (sort of like a moringa tree but this is not that). Grows straight up, has thorns on it. Have not been here long enough to see flowers if any, although an older one is in front yard as tall as a regular tree. The foliage is sparse as in a desert type plant. This is spreading like mad in the back of the yard after heavy rains. It is in front of some bamboo. I dug out all the small ones in my garden plot and left some at the edge thinking they would keep the invasive bamboo from encroaching more. Did I do the right thing? Do you know what this is? Cannot find anywhere on line.

ANSWER:

There are several native trees that grow in Austin that are similar to your description. The one that first comes to my mind, however, is Prosopis glandulosa (Honey mesquite). It is fast-spreading, has thorns and its leaves are as you describe. Here is more information from Aggie Horticulture and here is more than probably you wanted to know about mesquite from the Texas State Historical Society Texas Almanac. It is a problem plant in some situations. Ranchers and farmers are often eager to remove large stands of mesquite from their pastures and Texas A&M AgriLIFE Texas Natural Resoruces Server has advice on how to do this. This is a bit much for your backyard, but you can use herbicides judiciously to help eliminate mesquite (or whatever your unwanted tree is). Cut the stem or trunk of the tree and then immediately paint it with one of the herbicides (RoundUp, Remedy) using a plastic foam paint brush. Alternatively, you could pour a small amount of herbicide over the cut stem. Be caredul that none of the herbicide gets on any plants that you want to keep and be sure to read the herbicide label carefully and follow the safety instructions found there.

Here are some others that also could be candidates:

Parkinsonia aculeata (Retama) Here is more information from Floridata.
Acacia farnesiana (Huisache)
Acacia roemeriana (Roundflower catclaw)
Gleditsia triacanthos (Honey locust)
Mimosa aculeaticarpa (Catclaw mimosa) Here are photos and more information from and Northern Arizona Flora.

Now, for the bamboo issue, there isn't really a plant that will keep it from encroaching. If you are interested in trying to eliminate bamboo, please read the answer to a previous question.