Friday, February 08, 2008

Mutant Acorn?

I found this while out on a hike with my friend Yvonne. Neither of us could figure out what it was. My best guess is that it's a mutant acorn.

As you can see, it's attached to the oak leaf. Not at all like a wasp nest or anything. So....as Photo Friday asks: What Is That?
Thanks to Mary for providing the answer. It is an Oak Apple Gall. Read her comments on this post to find out more about it. Here's a look at the inside of it:

7 comments:

ahniwa said...

If I had to guess, I'd say it looks more like a walnut. They have a weird green skin on them that could shrivel up and end up looking like that.

Kathe said...

It does look sort of like a walnut, except it has the texture more like a leaf. And this is attached to an oak leaf. The last I knew, walnuts don't grow on oak trees. ;^)

Mary Stebbins Taitt said...

It's an oak leaf ball gall caused by a parasite that releases a chemical that causes it to grow.

Mary Stebbins Taitt said...

Oak Apple Galls

Oaks appear to be the most popular choice for the gall makers of North America. Most oak galls are caused by small wasps called cynipids or gall wasps. About 80 percent of the more than 700 different species of gall wasps in the United States produce galls specifically on oak trees. Most noticeable of the oak galls produced by the gall wasp are the golf-ball-sized oak apple galls.

Oak apple galls form on leaf stems or veins that run down the center of the leaf. Springtime oak apple galls look like little green apples, thus accounting for their name. The green galls blend with the leaves, but those that turn brown in summer are easy to see.

Mary Stebbins Taitt said...

http://www.cals.ncsu.edu/course/ent525/close/gallpix/pages/Gall10_jpg.htm

Mary Stebbins Taitt said...

excellent discussion here: http://earthfriendlygardening.wordpress.com/2006/10/24/of-all-the-gall/

Kathe said...

*smacking my head* DUH! I remember these NOW! Apparently, I was making the connection with the wasps and leaves somewhere in this tiny brain of mine. But, as usual, there must have been some sort of interference with my brain waves. Heh heh. Thanks so much, Mary!