Starkey Hill Interpretive Trail Highlights

Galls: abnormal growths on trees

Do trees get warts? Tree galls are abnormal growths, usually caused by infestations of insects, fungi or parasites. They can appear as small nodules on leaves and twigs or as larger, woody growths on branches and tree trunks. The very visible growth on the tree at this site is a good example of a large tree gall. Generally, galls don't significantly affect the health of a tree and are similar to benign warts or tumors in humans. Wood carvers often seek out galls of certain trees (oak burls, for example) for their interesting grain patterns. You may have seen bowls and other wood objects made from them.

Around you are quite a few trees with galls. Now that you know what to look for, how many tree galls can you spot?

Large tree gall
(photo Tim Johnson)

Want to know more about galls and burls? Go to

The Starkey Hill Interpretive Trail is jointly managed by the Guelph Hiking Trail Club and the Grand River Conservation Authority

Grand River Conservation Authority

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