Friday, March 6, 2009

Mystery Solved

Phomopsis gall on bitternut hickory limb

Here's an update about those warty looking tree "tumors" I wrote about in my February 24 post.  According to Moreau Park staffer Dave Alfred, the trees were all bitternut hickory.  There were about 20 hickories showing these growths in that particular low-lying area, and no other tree species nearby appeared to be affected.  Dave shared this information with Casey Holzworth,  regional biologist with the NYS Office of Parks, Recreation, and Historic Preservation.  This is what Casey  reported:

[These growths] appear to be phomopsis galls on hickory. It's a relatively common gall in hickory and some other species caused by some species of phomopsis fungus.  It will harm the vigor of the tree, but that's more of a concern for cultivators of some of the other species that this fungus can impact.  [Moreau Lake] Park staff will keep an eye on it.

 So now we know that it's just a fungus among us.  Not some alien invasion.  Phew!


John W. Wall said...

Maybe solved, but I'd still be tempted to cut into one to make sure it's not an insect gall!

Woodswalker said...

Thanks for your comment, John Wall. I tried to cut into one of these galls, but it was hard and solid, not hollow like many insect galls. According to information published by the Minnesota Dept of Natural Resources, "when cut open they consist of woody tissue that is a bit disorganized in comparison to the normal wood." I would say that was an understatement!

Linda said...

My pignut hickory has these galls on a lot of the leaf stems & the leaves are dropping off the tree. Is there anything I can do? I cut into one of the galls, no insects just hard & woody, but there are spots on the leaves that look like insect galls. Sure hope this isn't a death sentence for my tree. :o(

Anonymous said...

Thanks for your post. I live near Ottawa Ontario, Canada and have a large bitter hickory next to the house covered with these growths. It started about five years ago and more appear each year. It has spread to two other trees in the forest, but I don't think they are hickory. I'll have to check that. I feel better knowing what this is. I was sharpening the chainsaw because the emerald ash bore has killed a tree right next to the hickory. I will leave the hickory to live out it's days. It's about 35 years old and 10 inches in diameter.