Tree galls are rarely cause for concern - Forestry
Oak apple - Wikipedia
Oak Galls: What Are Oak Galls | Davey Tree
What's wrong with my plant? : Garden : University of Minnesota Extension
Oak Galls and Mistletoe: Nature's Decorations - The Real Dirt Blog - ANR Blogs
Oak galls galore - Neil Sperry's GARDENS
What is growing on that oak tree?
What Are Oak Galls - Learn About Oak Apple Gall Treatment | Gardening Know How
What Are Oak Apple Galls? | Gardening Question - New England
Oak Galls
Oak Galls: What Are Oak Galls | Davey Tree
The Cool and Unusual — San Diego Canyonlands
Growths on Oak Leaves and Twigs :: Melinda Myers
Galls on Oak Leaves and Twigs | Horticulture and Home Pest News
Oak tree 'galls' are fairly harmless
Blame Wasps And Squirrels For All The Oak Leaves On Your Lawn | STLPR
August | 2014 | The Granada Native Garden Newsletter
Whole Oak Galls - Botanical Colors
Oak Gall Wasp | From the Ground Up - YouTube
What is growing on that oak tree?
Home, Yard & Garden Newsletter at the University of Illinois
How Wasps Make Beautiful and Complex “Oak Apples” | Brandywine Conservancy and Museum of Art
