What are these blister-like things on the leaves of my oak tree? Will it harm them? P.T., Tulsa The structure on your leaves is a common oak leaf gall and will not harm a mature tree. Galls are ...

A gall is an abnormal growth or swelling of a plant caused by hormones released from insects, mites, bacteria, or nematodes. They can appear on any part of the plant with vast variation in morphology, ...

It can be unnerving to find that the leaves of an oak or hackberry tree are as bumpy as a rock-covered seashore in late summer. Other trees’ leaves may break out in acne-like red spots or sport ...

Persisting in the winter months as ball-shaped shells on oak trees, galls, which are considered an eyesore by landscapers in the summer months, appear as a sort of curiosity in winter. What are these ...

While walking to the mailbox one sunny morning I saw odd-looking spheres hanging from one of the young white oaks. About the size of golf balls, they were white with a few brown spots and fuzzy.

The new research points to a similar system involving not seeds, but galls made by cynipid wasps on oak leaves. According to the team, two gall wasp species, Kokkocynips rileyi and Kokkocynips decidua ...