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
2 ratings

Tuesday - August 26, 2008

From: Grafton, MA
Region: Northeast
Topic: Diseases and Disorders
Title: Strange growth on oak tree
Answered by: Nan Hampton

QUESTION:

i have a very strange round segmented growth on a tree in my yard. i think the tree is a chinkapin oak and the growth is a reddish color. it looks like a ball with suction cups on it. it is very strange looking thing and I have not been able to id it anywhere!

ANSWER:

It sounds as if your tree has a gall.  This is a growth that the tree makes in response to an insect or another organism such as a mite or a fungus.  Many galls are caused by an insect laying its eggs in the tree.  The insect hatches inside the gall growth, feeds on the growth and then emerges from the gall to continue its life cycle.  Here is more information about oak galls from the University of Kentucky and here is a Gallery of Common Galls from North Carolina State University.  Your growth sounds a bit like a horned oak gall.  If you don't find your growth in one of these links, please send us a photo and we will do our best to identify it.  Please visit the Ask Mr. Smarty Plants Plant Identification page to read instructions for submitting photos.

Note from Mr. SP:  After this answer was posted, someone else sent us a photograph that sounds very much like the gall described above.  We submitted the photo to BugGuide.net and asked if anyone could identify it.  Someone did identify it as being made by a gall wasp, Adleria quercusstrobilana, in the (Family Cynipidae), laying its eggs in the stem of the tree.

 

More Diseases and Disorders Questions

Danger of oak wilt infestation in trees with storm-damaged limbs
June 15, 2007 - A recent severe storm in Southwest Austin broke large branches and trunks on many Live Oaks in my neighborhood, including my next door neighbors'. Can this invite Oak Wilt? I'm worried about my tree...
view the full question and answer

Sooty mold on Sophora secundiflora in San Marcos, TX.
September 23, 2010 - Dear Mr. SP, We have a Sophora secundiflora that is suffering with very black mold or fungus on most of its leaves. Last year, I washed it leaf-by-leaf with soapy water but it's getting too big t...
view the full question and answer

Replacement Yaupon holly doing poorly in Pflugerville, TX
May 09, 2012 - I had to replace quite a few shrubs after the drought last year. I live in Austin, TX. I have planted 3 dwarf yaupon holly bushes in the exact same place where the previous three same type of shrubs...
view the full question and answer

Leaf problems on oaks in North Liberty IA
June 12, 2010 - My oak trees (young and old) are showing leaf problems. Is there a disease or insect causing oak tree disease?
view the full question and answer

Texas wild olive tree
April 05, 2012 - I live in the Phoenix area. My Texas wild olive (Cordia boissieri) is about 5 years old, about 12 feet tall and has beautiful blossoms all year long. However, this past year (through all seasons...
view the full question and answer

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