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

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.