Cynipidae-gall wasps. They are numerous, small, and usually target oaks.

Erineum- describes a hairy or "pile-like" growth on the surface of a leaf, produced by a species of mites. Example

Eriophyidae- A family of mite, many of which produce erineum. See above.

Fusiform - tapered at both ends.

Leaf galls- a loose term for any gall that appears on a leaf or is induced in leaf matter. To browse leaf galls, click here.

Mammiform - describes a gall which is "nipple" like in shape. Example.

Oak Apples - a common term for the type of large, spherical gall produced on an oak due to the activity of certain Cynipids. To browse Oak Apples, click here.

Pouch galls - a type of gall characterized by a depression in the leaf surface. These are usually caused by mites or aphids.

Stem galls (or twig galls) - a gall which affects the stem or the twig of a plant. This usually refers to a gall covering the "entire circumference of the stem or twig." To browse stem galls or twig galls, click here.

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